When his longtime former teammate Bart Starr was fired after nine years as head coach of the Packers in December 1983, Gregg was allowed out of his Bengals' contract to take over in Green Bay. He finished his NFL coaching career with the Packers, leading them for four seasons, 1984–1987, with a record of 25-37-1. Gregg's overall record as an NFL coach was 75 wins, 85 losses and one tie. He was also 2-2 in playoff games, all with the Bengals.