Marchibroda was drafted in 1953 by his hometown Pittsburgh Steelers. After one year, he left the Steelers to serve in the U.S. Army. After his discharge, Marchibroda returned to the Steelers. He finished his professional playing career with the Chicago Cardinals.
Marchibroda got his first head coaching job with the Baltimore Colts in 1975. In his first year, he turned the Colts into an instant playoff contender as they won the AFC East title. The Colts would win the AFC East title the next two seasons, led by 1976 NFL Most Valuable Player quarterbackBert Jones and sensational running backLydell Mitchell. But in those three playoff seasons, the Colts would lose in the AFC Divisional Playoffs including a 37–31 loss to the Oakland Raiders in the 1977 postseason. Marchibroda stayed as coach until 1979.
Marchibroda served as the quarterbacks coach and later offensive coordinator of the Buffalo Bills under head coach Marv Levy from 1987 to 1991. As offensive coordinator for the Bills, he was influential in the evolution of the hurry-up offense. Levy, Marchibroda and quarterback Jim Kelly used their version of the hurry-up offense, the "K-Gun" offense, more than any previous offense. Kelly would hurry to the line of scrimmage, preventing the defense from making substitutions, and called audibles at the line. The National Football League later imposed a rule that allowed time for defense substitutions if the offense made substitutions, except after the two-minute warning of either half.
In 1992, Marchibroda returned to the Colts for a second stint as head coach. He was fired by the Colts after the 1995 season. From 1996 to 1998 he coached the Baltimore Ravens, making him the only man to serve as head coach for both Baltimore NFL teams. He compiled a career record of 87–98–1, with a 2–4 record in the playoffs.
*Tied for 1st place in their division, but since there was no tie-breaking system in 1965, a game was played to determine who went to the conference championship. The Colts lost the divisional playoff game.