Minter won the bronze medal at the 1972 Munich Olympic Games. Soon after, Minter began his professional career in London on Halloween night of the same year by knocking out Maurice Thomas in six rounds.

Minter won five fights in a row by knockout, and in 1973, Pat Dwyer became the first boxer to go the distance with him, over eight rounds in London. 

1975 was the year that saw Minter shine. He won four fights in a row, including another bout in Hamburg, and by the end of the year, he challenged Kevin Finnegan for the British Middleweight title, winning it by a 15 round decision. 

In 1977, he won the European Middleweight title by beating GermanoValsecchi by a knockout in five in Italy. On March 16 1980, he was given a shot at champion Vito Antuofermo's world Middleweight title. He won the title by a 15 round decision, and in a rematch, he retained the world title by a knockout in eight rounds.

Minter's run as world champion came to an end on September 27 of that year, when he lost by a knockout in three to Marvin Hagler at Wembley Arena in London. 

Minter retired from the sport in 1981. He left boxing with a record of 39 wins, 9 losses and 1 no contest, with 23 wins by knockout. 

Currently he tours the UK in autograph and lecture shows and is becoming well known on the after dinner speaking circuit.