Edwards became a full-time starter with the Steelers as a free safety in 1973, and in 1974 won the award as Most Valuable Steeler. Edwards won two championship rings (Super Bowl IX and Super Bowl X) and made two Pro Bowl appearances after the 1975 and 1976 season. Edwards is also known for two key plays in his Super Bowl appearances. In Super Bowl IX, he laid a hit on Minnesota Vikings receiver John Gilliam just as Gilliam caught a pass near the goal line. The ball popped out of Gilliam's hands and into the arms of Steelers cornerbackMel Blount for an interception, killing the Vikings' drive. In Super Bowl X, he sealed a victory for Pittsburgh by intercepting a pass from Dallas Cowboys quarterback Roger Staubach in the end zone as time expired in the game. Edwards was a member of Pittsburgh's famed Steel Curtain defense, and he also returned punts and kickoffs for the Steelers. He was traded to the Chargers for a 1979 6th round pick in August 1978. With the Chargers, he recorded an interception in their famous 1982 AFC playoff victory known as The Epic in Miami.
Edwards finished his 11 NFL seasons with 39 interceptions, which he returned for 961 yards and 3 touchdowns. He also recovered 13 fumbles, returned 104 punts for 959 yards, and gained 257 yards on 13 kickoff returns.