Daniel Thursz, 71, the executive vice president of the Jewish service organization B'nai B'rith International from 1978 to 1988 and who was on its board of governors at the time of his death, died Jan. 18 at his home in Bethesda of a heart arrhythmia.

Dr. Thursz was born in Morocco and moved to the United States with his family in 1941. In the 1950s, he received a bachelor's degree in political science from Queens College in New York as well as master's and doctorate degrees in social work, both from Catholic University.

He was a program director at the D.C. Jewish Community Center until the mid-1950s and worked at B'nai B'rith until the early 1960s.

Dr. Thursz taught social work at Catholic University from 1960 to 1964 and at the University of Maryland in Baltimore, eventually serving as dean of Maryland's social work and community planning school from 1967 to 1977.

At his death, he was a social work professor at Catholic University and directed its Center on Global Aging. In the 1980s and 1990s, Dr. Thursz was on various councils on aging, among them the White House Conference on Aging's policy committee, and he served as chairman of the Leadership Council of Aging Organizations.

He was president emeritus of the National Council on Aging, where he had served from 1988 to 1995, and president of the International Federation on Aging.

Among the social work organizations at which he held top positions, Dr. Thursz was president of the Conference of Jewish Communal Service and the Maryland Conference on Social Welfare.

He was a board member of Sage Publications, which publishes academic journals.

His memberships included Adat Shalom Congregation in Bethesda.

He served in the Army during the Korean War.

Survivors include his wife of 47 years, Hadassah Neulander Thursz, of Bethesda; four children, Deborah Bleiweis of Cortlandt Manor, N.Y., David Thursz of Baltimore and Deena Klopman and Tamar Truland, both of North Potomac; and eight grandchildren.