FOR IMMEDIATE RELEASE
August 29, 2006

	Listed Stock Name:	Eisai Co., Ltd.
	President & CEO:	Haruo Naito
	Headquarters:	4-6-10 Koishikawa, Bunkyo-ku, Tokyo
	Securities Code:	4523
	Listed Locations:	First Sections of the Tokyo Stock Exchange & the Osaka Securities Exchange
	Inquiries:	Akira Fujiyoshi Vice President Corporate Communications, Investor Relations Phone: +81-3-3817-5120

Notice Concerning Acquisition of the Company's Own Shares through ToSTNet-2

(August 29, 2006)- Eisai Co., Ltd. today announced the decision on the method of acquisition of the company's own shares, pursuant to item 1 of Article 459 of the Corporate Law and the articles of incorporation.

1. Method of Acquisition
	Shares will be purchased at the Tokyo Stock Exchange at 8:45 a.m. on August 30, 2006 by a closing price of 5,530 per share as of today, August 29, 2006. Transactions (closing price transaction) will be made through ToSTNeT-2, and shall neither be made by other trading systems nor at another time. The purchase order will be valid only at the time designated for transactions.
2. Contents of Acquisition
	(1) Type of shares to be acquired	Common Stock
	(2) Total number of shares to be acquired	2 million shares
	(Note1)  The number of shares will not be changed. Depending on market fluctuations and other factors, a part or all of the transaction may not be performed. (Note2) The purchase is to be made by selling orders corresponding to the number of shares planned to be acquired.
3. Acquisition Disclosure
	The result of the transaction will be disclosed after the completion of the transaction which will start at 8:45 a.m. on August 30, 2006.

	(Reference)
	Outline of the acquisition plan of the company's own shares authorized by the Board of Directors (announced on July 31, 2006)
	(1)	Type of shares to be acquired	Common Stock
	(2)	Total number of shares to be acquired	4 million shares (maximum)
	(3)	Total value of shares to be acquired	22 billion Yen (maximum)
	(4)	Progress as of August 29, 2006 Total number of shares acquired    0 Total value of shares acquired     0