Under head coach Mike Ditka, who won the 1985 NFL Coach of the Year Award, the Bears went 15-1 in the regular season, becoming the second NFL team to win 15 regular season games, while outscoring their opponents with a staggering margin of 456-198. The Bears' defense, "46 Zone", allowed the fewest points (198), total yards (4,135), and fewest rushing of any team during the regular season (1,319). They also led the league in interceptions (34) and ranked third in sacks (64).
Pro Bowl quarterback Jim McMahon provided the team with a solid passing attack, throwing for 2,392 yards and 15 touchdowns, while also rushing for 252 yards and three touchdowns. Running back Walter Payton, who was then the NFL's all time leading rusher with 14,860 yards, rushed for 1,551 yards. He also caught 49 passes for 483 yards, and scored eleven touchdowns. Linebacker Mike Singletary won the NFL Defensive Player of the Year Award by recording three sacks, three fumble recoveries, and one interception.
But one of the most distinguishable players on defense was a large rookie lineman named William "Refrigerator" Perry. Perry came into training camp before the season weighing over 380 pounds. But after Bears defensive coach Buddy Ryan told the press that the team "wasted" their first round draft pick on him, Perry lost some weight and ended being an effective defensive tackle. He got even more attention when Ditka started putting him in the game at the fullback position during offensive plays near the opponent's goal line. During the regular season, Perry rushed for 2 touchdowns, caught a pass for 1, and was frequently a lead blocker for Payton during goal line plays.
The Bears "46 defense" also had the following impact players: On the defensive line, Pro Bowler and hall of famer Richard Dent led the NFL in sacks for the second year in a row with 17, while Pro Bowler and future hall of famer Dan Hampton recorded 6.5 sacks, and nose tackle Steve McMichael compiled 8. In addition to Singletary, linebacker Otis Wilson had 10.5 sacks and 3 interceptions while Wilber Marshall recorded 4 interceptions. In the secondary, defensive back Leslie Frazier had 6 interceptions, Mike Richardson recorded 4 interceptions, Dave Duerson had 5 interceptions, and Gary Fencik recorded 5 interceptions and 118 tackles.
Chicago's main offensive weapon was Payton and the running game. A big reason for Payton's success was fullback Matt Suhey as the primary lead blocker. Suhey was also a good ball carrier, rushing for 471 yards and catching 33 passes for 295 yards. The team's rushing was also aided by Pro Bowlers Jim Covert and Jay Hilgenberg and the rest of the Bears offensive line.
In their passing game, the Bears primary deep threat was wide receiver Willie Gault, who caught 33 passes for 704 yards, an average of 21.3 yards per catch, and returned 22 kickoffs for 557 yards and a touchdown. Tight end Emery Moorehead was another key contributor, catching 35 passes for 481 yards. Wide receiver Dennis McKinnon was another passing weapon, recording 31 receptions, 555 yards, and 7 touchdowns. On special teams, Kevin Butler set a rookie scoring record with 144 points, making 31 of 37 field goals (83%) and 51 of 51 extra points.