Krouse was selected by the New York Giants in the second round (25th overall) of the 1951 NFL Draft. The 1951 Giants defense he was part of, allowed the fewest total yards and rushing yards in the NFL for that season. 1952 was said to be his best professional year. On April 26, 1956, he was traded to the Detroit Lions in exchange for defensive tackle Dick Modzelewski.
Krouse was a part of the 1958 NFL Championship Game against the New York Giants, famously known as "The Greatest Game Ever Played". The 1958 Colts defense he was part of, allowed the fewest rushing yards in the NFL for that season. He contributed to the Colts winning back to back NFL titles in 1958 and 1959 against his old team, the Giants.
The Washington Post on April 10, 1966 said, "Raymond Francis Krouse, one of the finest athletes ever to come out of Washington, died yesterday at Georgetown University Hospital of a liver ailment." He left behind a wife, Majorie; four daughters (Karen, 14, Kimberly, 8, Carolyn, 5, and Kathy, 4 [ages at the time of his burial]); his mother, Mrs. Josephine Krouse; a sister, Mrs. Margaret Haney; and a brother, William (Sully) Krouse. He was buried on April 13, 1966, at Arlington National Cemetery, listed as a veteran of the U.S. Navy, WWII, nearby his son, David Edward, who died in 1963, after living two days.