The all-time leader in tackles (2,049) for the Broncos, Gradishar never missed a game, playing in 145 consecutive matches. He led all Broncos defenders in tackles nine consecutive years, including his final season in 1983. He accounted for 33 turnovers during his career, on 20 interceptions and 13 fumble recoveries. In 1980, against the Cleveland Browns, he returned an interception a team-record 93 yards for a touchdown. It was one of the four career touchdowns he scored. Twice his teammates voted him defensive MVP, first in 1978 then again in 1980.
In 1983, after 10 seasons of play, four of which the team advanced to the playoffs, Gradishar, after one final Pro Bowl appearance, decided to go out on top and announced his retirement at the relatively young age of 31.