Gentile was capped on 71 occasions by Italy between 1975 and 1984, scoring a single goal during his international career. He played in all of Italy's matches at the 1978 World Cup, where Italy finished in fourth place, after reaching second place in the final group stage of the tournament and then losing the 3rd place playoff to Brazil. Gentile also played in the 1980 European Championship, and he was named in the team of the tournament.