Mario Sitri competed at the 1956 Olympics in boxing and then in 1957 won a silver medal in the featherweight class at the European Championships, after which he turned professional. Sitri fought as a pro through 1968, with a career record of 33 wins, 25 losses and 2 draws. In 1959 he won the Italian bantamweight championship, and in 1961 the Italian featherweight championship, losing both titles after only a few months. In 1962 he regained the Italian featherweight crown, losing it again in his next bout two months later.
|1956 Summer||20||Melbourne||Boxing||Men's Bantamweight||Italy||ITA||5T|
|1956 Summer||20||Melbourne||Boxing||Italy||ITA||Quarter-Finals||Match #1||2||1956-11-28||Gilroy (IRL) , Sitri (ITA)|
|1956 Summer||20||Melbourne||Boxing||Italy||ITA||Round Two||Match #2||1||1956-11-26||Sitri (ITA) , Rashid (PAK)||decision|
|1956 Summer||20||Melbourne||Boxing||Italy||ITA||Round One||Match #4||1||1956-11-23||Sitri (ITA)||bye|