During his time in the WWWF, Koloff weighing in at wrestled WWWF World Heavyweight Championship title matches against Sammartino, Morales, Superstar Billy Graham and Bob Backlund, holding the distinction, with fellow villain Stan Stasiak, as one of only two men to challenge all four of these champions. Koloff would also be the first opponent to ever challenge for the WWWF World Heavyweight Championship in a steel cage match in a rematch loss against Sammartino. He fought in the WWWF from 1975 to 1976, 1978–1979 and 1983.