Educated at De La Salle College, he played with Richmond Thirds whilst still at school, and whilst still also playing for his school side. He made his senior debut in 1964 at the Punt Road Oval, against South Melbourne, on 25 July.). He played the next 33 consecutive games for Richmond's First XVIII, winning Richmond's Most Determined Trophy in 1966.
Richmond
Frank, who was very courageous and very skillful, developed into a very valuable member of the Richmond senior side. In the round 15 match against Collingwood, at the Melbourne Cricket Ground on 6 August 1966, Frank was chasing the ball somewhere between the forward-flank and centre-half forward, bent over, with his head down, concentrating on the ball, and his hands nearly at ground level, when Paddy Guinane, running at full tilt from full-forward, bounced off Mick Erwin, and smashed into Frank's head with one of his massive thighs at full force. It was obvious that, for some inexplicable reason, Guinane had not seen Frank; and because Guinane was having one of his intermittent bad days, it is most likely he was running to get to centre-half forward, and was looking up the ground into the distance. Guinane nearly killed him; Dimattina was very, very badly concussed, and had a broken nose. He was replaced by the 19th man, Kevin Bartlett; and, from that time, Bartlett was never again selected as a reserve . Dimattina played the next match as first rover, but was replaced during the match because of an injured knee, and did not play for the rest of the year. He played six senior games in 1967, and one in 1968; however, he was never able to regain his playing form and, in, particular, he never again displayed the fearless self-confidence and the well-balanced ball skills that had been so characteristic of his play prior to that collision. Richmond released him at the end of the 1968 season.
1969-1970: North Melbourne Football Club Seniors, 14 games
1971-1974: Brunswick Football Club, 64 games
1975: Sorrento Football Club, captain-coach
Post Football
Following his football career, Frank was the Richmond Senior Team Manager from 1988 to 1990. He is the owner of several restaurants, the first being the Il Gambero restaurant in Lygon Street, Carlton. His son, Paul Dimattina played 131 games for Footscray.