Dr. Nicholas Mallis, a retired urologist, died of heart disease Jan. 5 at his Timonium home. He was 83.

Born in Sparrows Point, he was a 1942 City College graduate and served in the Army during World War II.

He earned a bachelor's degree at the University of Maryland, College Park and his medical degree at the University of Maryland School of Medicine.

In the late 1940s, he was assistant chief of urology at the Walter Reed Army Hospital and went into private practice in Southwest Baltimore. He was chief of urology at St. Agnes Hospital for many years and was president of its medical staff from 1965 to 1966. He retired about 20 years ago.

Survivors include two sons, Nicholas Mallis Jr., of Wayne, N.J., and the Rev. Steven Michael Mallis of Mars Hill, N.C.; and four grandchildren. His wife of 50 years, the former Jean E. Nilsson, died in 1998.

Services were held Wednesday at Epiphany Episcopal Church, where he was a founding member.