Merck & Co., Inc.
P.O. Box 100
Whitehouse Station, NJ 08889-0100
(908)423-1000
March 20, 2003

Q: Why did I receive this proxy statement?

A: The Board of Directors is soliciting your proxy to vote at the Annual Meeting because you are a stockholder at the close of business on March 7, 2003, the record date, and are entitled to vote at the meeting.

This proxy statement and 2002 annual report, along with either a proxy card or a voting instruction card, are being mailed to stockholders beginning March 20, 2003. The proxy statement summarizes the information you need to know to vote at the Annual Meeting. You do not need to attend the Annual Meeting to vote your shares.

Q: What is the difference between holding shares as a stockholder of record and as a beneficial owner?

A: If your shares are registered directly in your name with Merck’s transfer agent, Wells Fargo Bank Minnesota, N.A., you are considered, with respect to those shares, the “stockholder of record.” The proxy statement, annual report and proxy card have been sent directly to you by Merck.

If your shares are held in a stock brokerage account or by a bank or other nominee, you are considered the "beneficial owner" of shares held in street name. The proxy statement and annual report have been forwarded to you by your broker, bank or nominee who is considered, with respect to those shares, the stockholder of record. As the beneficial owner, you have the right to direct your broker, bank or nominee how to vote your shares by using the voting instruction card included in the mailing or by following their instructions for voting by telephone or the Internet.

Q: What is "householding" and how does it affect me?

A: Merck has adopted the process called “householding” for mailing the annual report and proxy statement in order to reduce printing costs and postage fees. Householding means that stockholders who share the same last name and address will receive only one copy of the annual report and proxy statement, unless we receive contrary instructions from any stockholder at that address. Merck will continue to mail a proxy card to each stockholder of record.

If you prefer to receive multiple copies of the proxy statement and annual report at the same address, additional copies will be provided to you promptly upon request. If you are a stockholder of record, you may contact us by writing to Merck Stockholder Services, P.O. Box 100, Whitehouse Station, NJ 08889-0100 or by calling our toll-free number 1-800-613-2104. Eligible stockholders of record receiving multiple copies of the annual report and proxy statement can request householding by contacting Merck in the same manner.

If you are a beneficial owner, you may request additional copies of the proxy statement and annual report or you may request householding by notifying your broker, bank or nominee.

Q: Can I access the proxy statement and annual report on the Internet instead of receiving paper copies?

A: This proxy statement and the 2002 annual report are located on Merck’s web site. Most stockholders can access future proxy statements and annual reports on the Internet instead of receiving paper copies in the mail.

If you are a stockholder of record, you can choose this option by marking the appropriate box on your proxy card or by following the instructions if you vote by telephone or the Internet. If you choose to access future proxy statements and annual reports on the Internet, you will receive a proxy card in the mail next year with instructions containing the Internet address for those materials. Your choice will remain in effect until you advise us otherwise.

If you are a beneficial owner, please refer to the information provided by your broker, bank or nominee for instructions on how to elect to access future proxy statements and annual reports on the Internet. Most beneficial owners who elect electronic access will receive an e-mail message next year containing the Internet address for access to the proxy statement and annual report.

Q: What am I voting on?

A:

• Election of five directors: Mr. Lawrence A. Bossidy, Dr. Johnnetta B. Cole, Mr. William B. Harrison, Jr., Dr. William N. Kelley and Dr. Heidi G. Miller;
• Ratification of the appointment of PricewaterhouseCoopers LLP as independent public accountants for 2003; and
• Adoption of the 2003 Incentive Stock Plan.

The Board recommends a vote FOR each of the nominees to the Board of Directors and FOR the ratification of the appointment of PricewaterhouseCoopers LLP as independent public accountants for 2003 and adoption of the 2003 Incentive Stock Plan.

You will also vote on the following stockholder proposals:

• a proposal concerning annual election of directors;
• a proposal concerning director nominees;
• a proposal concerning extension of prescription drug patents; and
• a proposal concerning ethical and social performance of the Company.

The Board recommends a vote AGAINST the stockholder proposals.

Q: What is the voting requirement to elect the directors and to approve each of the proposals?

A: In the election of directors, the five persons receiving the highest number of affirmative votes will be elected. The ratification of the appointment of PricewaterhouseCoopers LLP as independent public accountants, adoption of the 2003 Incentive Stock Plan and approval of the stockholder proposals each require the affirmative vote of a majority of the votes cast. If you are present or represented by proxy at the Annual Meeting and you abstain, your abstention, as well as broker non-votes, are not counted as votes cast on any matter to which they relate.

Q: How many votes do I have?

A: You are entitled to one vote for each share of Common Stock that you hold, except for the election of directors. Because you may cumulate your votes in the election of directors, you are entitled to as many votes as equal the number of shares held by you at the close of business on the record date, multiplied by the number of directors to be elected.

Q: How do I cumulate my votes in the election of directors?

A: In connection with the cumulative voting feature for the election of directors, you are entitled to as many votes as equal the number of shares held by you at the close of business on the record date, multiplied by the number of directors to be elected. You may cast all of your votes for a single nominee or apportion your votes among any two or more nominees. For example, when five directors are to be elected, a holder of 100 shares may cast 500 votes for a single nominee, apportion 100 votes to each of five nominees or apportion 500 votes in any other manner by so noting in the space provided on the proxy card. Beneficial owners should contact their broker, bank or nominee to cumulate votes for directors. The cumulative voting feature for the election of directors is also available by voting in person at the Annual Meeting; it is not available by telephone or the Internet.

You may withhold votes from any or all nominees. Except for the votes that stockholders of record withhold from any or all nominees, the persons named in the proxy card will vote such proxy FOR and, if necessary, will exercise their cumulative voting rights to elect the nominees as directors of the Company.

Q: How do I vote?

A: You may vote using any of the following methods:

• Proxy card or voting instruction card. Be sure to sign and date the card and return it in the prepaid envelope. If you are a stockholder of record and you return your signed proxy card but do not indicate your voting preferences, the persons named in the proxy card will vote FOR the election of directors, the ratification of the appointment of PricewaterhouseCoopers LLP as independent public accountants for 2003 and adoption of the 2003 Incentive Stock Plan and AGAINST the stockholder proposals on your behalf.
• By telephone or the Internet. The telephone and Internet voting procedures established by Merck for stockholders of record are designed to authenticate your identity, to allow you to give your voting instructions and to confirm that these instructions have been properly recorded.
• The availability of telephone and Internet voting for beneficial owners will depend on the voting processes of your broker, bank or nominee. Therefore, we recommend that you follow the voting instructions in the materials you receive.
• In person at the Annual Meeting. All stockholders may vote in person at the Annual Meeting. You may also be represented by another person at the meeting by executing a proper proxy designating that person. If you are a beneficial owner of shares, you must obtain a legal proxy from your broker, bank or nominee and present it to the inspectors of election with your ballot when you vote at the meeting.

Q: What can I do if I change my mind after I vote my shares?

A: If you are a stockholder of record, you may revoke your proxy at any time before it is voted at the Annual Meeting by:

• sending written notice of revocation to the Secretary of the Company;
• submitting a new, proper proxy by telephone, Internet or paper ballot, after the date of the revoked proxy; or
• attending the Annual Meeting and voting in person.

If you are a beneficial owner of shares, you may submit new voting instructions by contacting your broker, bank or nominee. You may also vote in person at the Annual Meeting if you obtain a legal proxy as described in the answer to the previous question.

Q: Who will count the vote?

A: Representatives of IVS Associates, Inc. will tabulate the votes and act as inspectors of election.

Q: What shares are included on the proxy card?

A: The shares on your proxy card represent shares registered in your name as well as shares in the Merck Stock Investment Plan.

However, the proxy card does not include shares held for participants in the Merck & Co., Inc. Employee Savings and Security Plan, Merck & Co., Inc. Employee Stock Purchase and Savings Plan, Hubbard ISA LLC Employee Savings Plan, Medco Health Solutions, Inc. 401(k) Savings Plan, Merck Puerto Rico Employee Savings and Security Plan, Merck Frosst Canada Inc. Stock Purchase Plan ("Merck Frosst Plan"), MSD Employee Share Ownership Plan and Merial 401(k) Savings Plan ("Merial Plan"). Instead, these participants will receive from plan trustees separate voting instruction cards covering these shares. If voting instructions are not received from participants in the Merck Frosst Plan, the plan trustee will vote the shares in accordance with the recommendations of the Board of Directors. If voting instructions are not received from participants in the Merial Plan, the plan trustee will vote the shares in the same proportion as it votes shares for which voting instructions are received. Trustees for the other plans will not vote shares for which no voting instructions are received from plan participants.

Q: What constitutes a quorum?

A: As of the record date, 2,244,349,140 shares of Merck Common Stock were issued and outstanding. A majority of the outstanding shares, present or represented by proxy, constitutes a quorum for the purpose of adopting proposals at the Annual Meeting. If you submit a properly executed proxy, then you will be considered part of the quorum.

Q: Who can attend the Annual Meeting?

A: All stockholders as of the record date may attend the Annual Meeting but must have an admission ticket. If you are a stockholder of record, the ticket attached to the proxy card will admit you and one guest. If you are a beneficial owner, you may request a ticket by writing to the Office of the Secretary, WS 3AB-05, Merck & Co., Inc., P.O. Box 100, Whitehouse Station, New Jersey 08889-0100 or by faxing your request to 908-735-1224. You must provide evidence of your ownership of shares with your ticket request, which you can obtain from your broker, bank or nominee. We encourage you or your broker to fax your ticket request and proof of ownership in order to avoid any mail delays.

Q: Are there any stockholders who own more than 5 percent of the Company’s shares?

A: According to a filing made with the Securities and Exchange Commission on February 13, 2003, Fidelity, through its funds, subsidiaries and institutional accounts, owns approximately 5.4 percent of the Company’s outstanding Common Stock. See “Security Ownership of Certain Beneficial Owners and Management” on page 15 for more information.

Q: When are the stockholder proposals due for the 2004 Annual Meeting?

A: In order to be considered for inclusion in next year’s proxy statement, stockholder proposals must be submitted in writing by November 21, 2003 to Celia A. Colbert, Vice President, Secretary and Assistant General Counsel, WS 3A-65, Merck & Co., Inc., One Merck Drive, Whitehouse Station, NJ 08889-0100.

If you notify us after February 4, 2004 of an intent to present a proposal at the Company’s 2004 Annual Meeting, we will have the right to exercise discretionary voting authority with respect to such proposal, if presented at the meeting, without including information regarding such proposal in our proxy materials.

Q: What happens if a nominee for director is unable to serve as a director?

A: If any of the nominees becomes unavailable for election, which we do not expect, votes will be cast for such substitute nominee or nominees as may be designated by the Board of Directors, unless the Board of Directors reduces the number of directors.

Q: How much did this proxy solicitation cost?

A: Georgeson Shareholder Communications, Inc. has been hired by the Company to assist in the distribution of proxy materials and solicitation of votes for $22,000, plus reasonable out-of-pocket expenses. Employees, officers and directors of the Company may also solicit proxies. We will reimburse brokerage houses and other custodians, nominees and fiduciaries for their reasonable out-of-pocket expenses for forwarding proxy and solicitation material to the owners of Common Stock.

Q: What is the Company’s Web address?

A: The Merck home page is www.merck.com. You may also go directly to www.merck.com/about/corporategovernance for the following information:

• Policies of the Board—a statement of Merck’s corporate governance principles; and
• Merck Board Committee Charters—Audit Committee, Committee on Corporate Governance, and Compensation and Benefits Committee.