McCaskey had been battling a series of illnesses in recent years.
A popular figure within the NFL, McCaskey was the son-in-law of Bears founder George Halas and joined the Bears in 1967. He was often referred to as the "conscience" of the league as well as a sounding board for many of its leaders.
"Today the entire Bears organization suffered a great loss in the passing of Ed McCaskey," Bears president Ted Phillips said. "Ed's leadership and his love of life gave all of us at the Chicago Bears a real sense of family. He will be greatly missed."
One of McCaskey's favorite players was Brian Piccolo, who died of cancer. McCaskey was a consultant on the movie, "Brian's Song," which was based on Piccolo's life, and worked with the Piccolo Fund to raise millions of dollars for cancer research.
A graduate of the University of Pennsylvania, McCaskey served in World War II and won a Bronze Star and Combat Infantry Badge for his performance in combat.