Arthur Anthony Steffan, 73, a Washington attorney for more than 35 years who was general counsel of the American Petroleum Refiners Association, died Tuesday at the Sierra Vista Hospital in San Luis Obispo, Calif. He had a heart ailment.

Mr. Steffan was born in Buffalo, N.Y. He graduated from Canisius College there and then moved to Washington. He worked for the Passport Office and St. Elizabeth's Hospital while attending night classes at Georgetown University law school, from which he graduated in 1932.

For the next several years, he was in private practice in New York and Philadelphia. He returned to Washington in about 1940 and established a practice here. He maintained it until 1976, when he retired. He moved to San Luis Obispo in 1978.

Mr. Steffan helped organize the American Petroleum Refiners Association in about 1960 and served as its general counsel until his retirement.

Mr. Steffan was a member of the Knights of Columbus. He was a member of the parish of St. Dominic's Catholic Church for several years and of the parish of St. Thomas the Apostle Catholic Church at the time he moved to California.

Survivors include his wife, Alice (Jack) Steffan of San Luis Obispo; a stepson, John Gillham, also of San Luis Obispo; two stepdaughters, Mary Stageberg, of Oswego, Ore., and Kennedy James of Arlington; a sister, Genevieve Steffan, of Buffalo, N.Y., and 11 stepgrandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Nativity of Our Lady Church, 221 Daly St., San Luis Obispo, Calif. 93401.