Leonard M. Reamer, 45, a senior partner in the Washington accounting firm of Elmer, Fox, Westheimer & Co., died Thursday at Suburban Hospital in Bethesda following a heart attack.

He had been associated with the firm since 1965.

Mr. Reamer was on the board of directors of the Association of Government accountants and was chairman of education standards of the D.C. Institute of Certified Public Accountants and the continuing education committee of the Maryland State Society of Certified Public Accountants. He was a member of the Maryland State Board of CPAs.

He also belonged to the American Institute of Certified Public Accountants and the National Association of Accountants.

Mr. Reamer was a native of Baltimore. He earned a bachelor's degree at the University of Maryland.

He joined the accounting firm of Peat, Marwick & Co. in 1954. He was named manager of the Washington office in 1961, a post he held until leaving the company three years later.

He joined Elmer, Fox, Westheimer & Co. afte spending a year as secretary-treasuer of RACAL Communications, a Washington communications firm.

Mr. Reamer was a certified public accountant in both Washington and Maryland. He had been treasurer of the D.C. Junior Chamber of Commerce during the mid-1960s.

He was a member of the University of Maryland Alumni Association, was president of the Fastbreakers at the university and was a director of the Terrapin Club. He was serving as executive in residence at Maryland's College of Business and Management at the time of his death.

He was on the board of director of Beth Sholom Congregation in Silver Spring.

Survivors include his wife, Elinor, a son Bruce, and a daughter, Paula, all of the home in Bethesda; another daughter, Michele Schwitzky, of St. Louis; another son, Steven, of College Park, his mother, Jennie Reamer, a brother, Robert I., and a sister, Irma Jacobs, all of Baltimore.

The family suggests that expressions of sympathy be in the form of contributions to the Leonard M. Reamer Fastbreaker Scholarship Fund at the University of Maryland.