Dr. Arch Lockhart Riddick, 91, a surgeon who practiced in Washington for more than 40 years and also was a clinical professor of surgery at the George Washington University medical school, died of congestive heart failure Feb. 15 at the Woodbine nursing home in Alexandria.

Dr. Riddick, a resident of Washington until moving to the Woodbine about three years ago, was chief of surgery at Suburban Hospital in Bethesda from the time it opened in 1944 until 1960. He held the same post at the old Emergency Hospital, now part of the Washington Hospital Center, from 1947 to 1956. He was a member of the boards of directors at both hospitals.

He also was a member of the surgical staffs at the old Garfield Hospital, now also part of the Washington Hospital Center, at the old Doctors Hospital and at George Washington University Hospital.

He was a founding member of the American Board of Surgery and a member of the American College of Surgeons, the American Medical Association and the D.C. Medical Society, from which he received a citation for his help in establishing the Blue Cross and Blue Shield health insurance plans.

Dr. Riddick was born in Hertford, N.C. He graduated from Guilford College and earned his medical degree at Johns Hopkins University in 1921. He moved to Washington and did his residency in surgery at Emergency Hospital. He was appointed an assistant professor of surgery at the George Washington University medical school in 1925 and a clinical professor in 1934. He retired from teaching in 1959.

From 1924 to 1929, Dr. Riddick was an associate of the late Dr. Charles Stanley White. He then established his own practice and continued it until he retired in 1971.

Dr. Riddick was a member of the Cosmos and Metropolitan clubs and St. Albans Episcopal Church.

Survivors include his wife, Wilhelmina Riddick of Washington; two children, Arch L. Riddick Jr. of McLean and Anne Lee Speck of Vista, Calif.; a sister, Tess Page of Austin, Tex.; six grandchildren, and two great-grandchildren.