After short stints with the Philadelphia Eagles and the Bears, Gibron ended his playing career and got into coaching. He served first as a line coach for the Redskins for five years, and then in a similar role for the Bears beginning in 1965. He rose to become Bears' defensive coordinator in the early 1970s, and was named head coach in 1972, replacing Jim Dooley. Gibron's three years leading the Bears were unsuccessful, however. His teams posted a combined win–loss–tie record of 11–30–1 over three seasons. Gibron was fired in 1974, and spent the following year as coach of the Chicago Winds, a team in the short-lived World Football League.