McTaggart competed at two Olympic games as a Lightweight (1956, 1960), and one as a Light welterweight (1964). McTaggart won the gold medal in 1956, and was awarded the Val Barker Trophy, as the games outstanding boxer. He won the bronze medal in 1960, and was eliminated in the 3rd round in 1964. McTaggart was also a five-time ABA champion (1956, 1958, 1960, 1963 and 1965). McTaggart purportedly won 610 of his 634 amateur bouts.