Gamarro represented his native country at the 1976 Summer Olympics in Montreal, Quebec, Canada.

There, he won the silver medal in the welterweight division (– 67 kg) after having lost to Jochen Bachfeld of East Germany in the final.

A year earlier, Gamarro had won a bronze medal at the 1975 Pan American Games.

In between, he also won a bronze medal at the 1983 Pan American Games held in his home country.

[1] Below are the results of Gamarro at the 1976 Montreal Olympics: This biographical article related to a Venezuelan boxer is a stub.