Born in London of Italian extraction, Marino initially turned to boxing as a Cruiserweight. However unable to obtain a licence to box in the United Kingdom, he spent his entire career in mainland Europe.He turned to wrestling in the early 1950s and came to prominence after winning an international tournament in Paris in 1951. Mike Marino appeared on the first televised wrestling match in the United Kingdom, a bout against Francis Gregory at West Ham Municipal Baths (now Atherton Leisure Centre) on Wednesday 9 November 1955.
Marino won the World Mid-Heavyweight Championship in 1957 and went on to hold the title four times. The European Mid-Heavyweight Championship was added in 1967, although his claim was for a time disputed Bill Howes, with Marino eventually relinquishing his claim until Howes retirement. He eventually added the British Mid-Heavyweight Championship, winning the title in December 1966 and holding it until his death in 1981. Marino held all three belts when he died.
A regular on the main shows at the Royal Albert Hall, Marino was recognised as one of British wrestling's leading technicians of the era.He gained the nickname 'Mr. Wrestling' due to his ability and his length of service. Nonetheless Marino was one of a number of wrestlers to be caught up in a 'tabloid exposé' when in 1972 the News of the World published the transcripts of a dressing room conversation between Marino and his opponent Albert 'Rocky' Wall discussing how their upcoming match would be arranged. With British wrestling still operating full kayfabe, such stories exposing the scripted nature of the sport were common in the tabloids at the time.