Gomes made his senior international debut at 19, in a 1996 friendly against France. He scored his first goal in Portugal's opening match at the UEFA Euro 2000, marking his fourth start with the winner as the side came from two goals down to beat England 3–2. He would finish the competition with four goals as the national team reached the last four, but earned a seven-month international ban after pushing referee Günter Benkö following the semi-final defeat by France, in which he had opened the score; he was selected to the UEFA team of the tournament.