Dr. Joseph D. Casolaro, 60, an obstetrician and gynecologist in Arlington and a clinical professor at the Georgetown University medical school until his retirement in 1975, died of leukemia April 30 at the University of Miami Hospital in Miami.

Dr. Casolaro, who lived in Waterford, Va., had gone to Miami for treatment.

A native of New York City, he graduated from Fordham University and earned his medical degree at the Long Island College of Medicine. He served in the Army in World War II and moved to the Washington area in 1947.

In the 1960s, Dr. Casolaro helped found Bionetics, which specializes in cancer research. The firm is now called Litton Bionetics.

Dr. Casolaro was a member of the Northern Virginia Medical Society. He lived in McLean for many years and was active in fund-raising for St. John's Catholic Church there.

His marriage to Frances P. Casolaro ended in divorce.

Survivors include his wife, Ellen, of Waterford; five children by his first marriage, Mari-Ellen Felix, of Falls Church, Linda Oels, of Watchung, N.J., J. Daniel, of Fairfax, Dr. Anthony, of Atlanta, and John, of McLean; two stepchildren, Elizabeth and Allison Hall, both of Waterford, and nine grandchildren.