Capt. Wood Griffith van Valkenburgh, 46, a staff physician in the department of medicine of the National Naval Medical Center at Bethesda, died of cancer Tuesday at his home in Potomac.

Assigned to the center in 1970, he was head of the rheumatology branch of the Internal Medicine Service there. He was an associate professor of medicine at the Uniformed Services University of the Health Services Medical School in Bethesda.

Dr. van Valkenburgh was born in East Orange, N.J., and grew up in Suffolk, Va. He was a graduate of Virginia Polytechnic Institute in Blacksburg and the Medical College of Virginia in Richmond.

He entered the Navy and served his internship at the Bethesda Naval Medical Center. He served at sea from 1960 to 1962, then took further training in Philadelphia and Richmond. He was a staff physician at the Naval Hospital in Portsmouth, Va., before returning to the Bethesda facility. Dr. van Valkenburgh was a diplomate of the American College of Physicians, and was president of the District of Columbia Rheumatism Socity.

An accomplished pianist, he was a member of the Oratorio Society of Washington. He belonged to Christ Episcopal Church in Rockville, where he sang in the choir and directed a handbell ringing group.

he is survived by his wife, the former Ellen Ellis Thomas, a daughter, Elizabeth Carter, and a son, Paul Thomas, all of the home, and his parents, Paul R. and Elizabeth van Valkenburgh, of Suffolk.

The family suggests that expressions of sympathy be in the form of contributions to the memorial fund of Christ Church, or to the American Cancer Society.