Thomas L. Lambdin, 49, an employe of the Agriculture Department's Rural Electrification Administration and a resident of Vienna since 1962, died of cancer Tuesday at Fairfax Hospital.

He was born in Montcalm, W.Va., and reared in Princeton, W.Va. After serving in the Air Force, he earned a bachelor's degree in business administration at Concord College in Athens, W.Va.

Mr. Lambdin worked for the Boy Scouts of America and Montgomery Ward in West Virginia, then moved to Miami, where he sold life insurance. He moved to the Washington area in 1962. He was a public utility rates analyst with the REA.

He was a certified white water canoeist and a member of the Potomac Hunt Club.

Mr. Lambdin attended Wesley Methodist Church in Vienna.

Survivors include his wife of 29 years, the former Carolyn Rice, of Vienna; two sons, Thomas M., of Sterling, and Mark L., of Vienna; a daughter, Terri Lynn Michaely of Fairfax; his mother, Ethel Lambdin of Miramar, Fla.; two sisters, Ruth Lusk of Hollywood, Fla., and Ruby Lambdin of Whiteville, N.C., and two brothers, Robert L., of Miramar, and James F., of South Brunswick, N.J.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society.