After his professional playing career ended, Mariucci became the head coach of the
Minnesota Golden Gophers hockey team. He was noted for not attempting to sign Canadian players for his hockey teams, but instead relying on home-grown talent from Minnesota. This helped to grow youth and high school hockey programs in the state of Minnesota. He was coach at the university from the 1952–53 season until the 1965–66 season, except for the 1955–56 season in which he was the head coach of the
US Olympic team that won a silver medal. Mariucci's best Gopher team came in 1953–54 when Minnesota would advance all the way to the NCAA finals before losing to
Rensselaer Polytechnic Institute, 5–4 in overtime. In 1967, he was named the assistant to the general manager for the
Minnesota North Stars, with
Glen Sonmor becoming the Gophers' coach. He eventually worked for
Lou Nanne, one of his Gopher Hockey players, and held the position with the North Stars until his death in 1987. He returned to the international scene as the head coach of the United States team at the 1976 and 1977
Ice Hockey World Championships. He was involved in a bizarre confrontation with Nanne during the 1977 championships. After loudly criticizing Nanne during the game against the
Soviet Union, Nanne responded by charging his coach, which led to a fist fight while the game continued. After the game finished, the fight continued until both men were separated by players and officials. The University of Minnesota honored him by first renaming the hockey arena in
Williams Arena after him and later when a new hockey arena was opened in 1993, the school transferred his name to that one as well,
Mariucci Arena. In 1983, the John Mariucci Award, began to be awarded to the Minnesota High school coach of the year, as selected by the state's hockey coaches, as Mariucci is immortalized as the "Godfather of Minnesota Hockey". Upon his death, the Minnesota North Stars wore a memorial round patch, with initials JM within, for parts of the 1987–1988 season. ==Career statistics==