Morris Kaplan, 66, founder of Everybody's Grocery Store and Everybody's Car Wash in northwest Washington, suffered a heart attack Sunday morning at Beth Sholom Synagogue while giving a lecture. He was taken to Walter Reed Army Hospital, where he died.

Mr. Kaplan came to this country from Poland as a young man and lived for a short time in Boston before moving to Washington. He was active in the grocery business, establishing the former Everybody's Grocery Store at 15th and P St. NW. He later went into the car wash business, which is still active, calling his establishments Everybody's Car Wash. He had locations at 15th and P St. NW. Rockville, Hyattsville and Minnesota and Pennsylvania Avenues SE.

His latest activities were in the real estate and brokerage business. Six Months ago he formed Brokers Associates in silver Spring.

Mr. Kaplan was a member of B'nai B'rith, a past president of Argo Lodge, a member of the Samuel Gompers Masonic Lodge and the Progress Club.

Survivors include his wife, Edith, of the home in Sliver Spring; a son, Arnold, of silver Spring; two daughters, Diane Trossevin, of Silver Spring and Barbara Gonick, of Los Angeles, Calif,; two brothers, Carl, of Silver Spring, and Yudel, of Argentina, and eight grandchildren.