Dr. Christopher J. Murphy Jr., 62, a physician who maintained a practice in obstetrics and gynecology in Alexandria and was active in professional organizations, died Tuesday at Alexandria Hospital after a stroke.

Dr. Murphy was president of the Virginia Obstetrical and Gynecological Society from 1970 to 1971 and of the Alexandria Medical Society from 1954 to 1955. He had practiced medicine in Alexandria for more than 30 years and was a member of the staff of Alexandria Hospital at the time of his death.

He was a diplomate of the American Board of Obstetrics and Gynecology and a member of the American College of Surgeons and the Virginia Medical Society.

Dr. Murphy was a native of Washington and a graduate of Eastern High School. He attended Mount St. Mary's College in Emmitsburg, Md., and earned his medical degree at George Washington University. He served residencies at Providence and Georgetown University hospitals.

He served as a physician in the Air Force from 1946 to 1948.

Dr. Murphy, who lived in Falls Church, was the president of the Lake Barecroft Citizens Association from 1966 to 1967. He also had been active in the Alexandria Chamber of Commerce and the Rotary Club of Bailey's Crossroads. He was a 4th degree member of the Fairfax Council of the Knights of Columbus.

Survivors include his wife of 36 years, the former Jean Connelly, of Falls Church; a daughter, Gail A. Williams of Bremerton, Wash.; three sons, Christopher J. I.I.I., of South Bend, Ind., Gregory L., of Alexandria, and Brian P., of Santa Clara, Calif.; two brothers, Robert J., of Arlington, and William J., of Suitland; a sister, Catherine B. Liekweg of Alexandria, and 10 grandchildren.