Causio made his debut with Italian national football team on 29 April 1972 in a 0–0 draw against Belgium, in a 1972 European qualifying match. He was in the Italian squad at the 1974 World Cup, and at the 1978 World Cup, where the Italians finished in fourth place after reaching the semi-final. He also represented Italy at the 1980 European Championship on home soil, where they once again finished in fourth place after a semi-final finish. He was most notably a member of the Italian squad that won the 1982 World Cup. With two red cards throughout his international career, he is Italy's most red carded player ever, alongside Giancarlo Antognoni and Daniele De Rossi.