The WHL alumni entered the NHL in 1988-89 with the New York Islanders, who had previously drafted him 118th overall in the 1987 NHL Entry Draft. He would split the next few seasons between the Isles and their American Hockey League farm team before being drafted by the Tampa Bay Lightning in the 1992 NHL Expansion Draft. A season and a half later, DiMaio was dealt to the Philadelphia Flyers. In 1996, DiMaio joined the Boston Bruins. He played three seasons and a half there, before playing 12 games for the New York Rangers, one season with the Carolina Hurricanes, three with the Dallas Stars, the lock-out year in Europe with the SC Langnau and HC Milano, before returning to the Lightning in 2005.