Betty Tolbert Walters, 56, a secretary for Montgomery County public schools for the past 22 years, died Friday at George Washington University Hospital after a heart attack.

Mrs. Walters began working as a secretary for junior high schools in Montgomery County in 1958, and later worked in the school system's central office in Rockville. About eight years ago, when the system was split into five jurisdictions, she became secretary to the associate school superintendent for Area 5.

Mrs. Walters lived in Rockville. She was born in Washington and graduated from Coolidge Senior High School and attended American University. She was a member of the Coolidge Alumni Association.

Mrs. Walters was a member of Northwood Prebysterian Church in Silver Spring and Women in Education. She was a former member of the Washington Hawaiian Club.

Her husband, John A. Walters, a service manager for Woodward & Lothrop, died in 1966.

Survivors include two sons, John A. Jr., of Boyds, Md., and Stephen T., of Rockville; a brother, Samuel Tolbert of Centreville, Va.; five sisters, Virginia Minor and Jane Wootten, both of Silver Spring, Mary Sue Potzler of Wheaton, Ann Richardson of Bethesda, and Marjorie Babbage of Riverside, Calif., and two granddaughters.

The family suggests that expressions of sympathy be in the form of Contributions to the American Heart Association.