Marjorie A. Collins, 67, an associate director of the National Council on the Aging and a former social worker and consultant, died of a heart attack Thursday at George Washington University Hospital. She lived in Washington.

At the time of her death, Miss Collins was serving as director of the Council's Training and Conference Department.

She joined the staff of the NCOA, a nonprofit voluntary organization, in New York City in 1968 and came here the following year, when the Council moved its headquarters to Washington.

She previously lived here when she served as an assistant director and supervisor for the District chapter of the American Red Cross during World War II and, later, as director of volunteer services for the old United Community Services. During the war, she developed and headed a program of foreign industry and the prisoner of war department for the Red Cross. Earlier, she supervised volunteers for the Travelers Aid Society of Washington.

She served as a consultant for the old Department of Health, Education and Welfare, the Bureau of Family Services and VISTA.

Miss Collins was born in Cincinnati. She attended Dension University in Granville, Ohio, and completed a two-year program in Public Welfare Administration in Social Work at Columbia University School of Social Work.

She also had worked for the Ohio Humane Society, the Hamilton County, Ohio, Public Welfare Department and for the Volunteer Service Bureau here in New York City.

Survivors include her husband, John Larry Smith of Washington, and two sisters, Dorothy C. Armstrong of Saginaw, Mich., and Katherine C. Cox of Philadelphia.

The family suggests that expressions of sympathy be in the form of contributions to the National Council on the Aging Inc. in Washington.