Oblak's debut for the Yugoslav national team came in a friendly match against Romania in 1971. The same year he had the honour of playing at Pelé's farewell match at the Maracanã in Rio de Janeiro. At the 1974 World Cup in Germany, he and his teammate Danilo Popivoda became the first Slovenians to play in a World Cup. Even more impressive is that Oblak was selected into the best squad of the World Cup. In 1976, he played at the European Championship, which was hosted by Yugoslavia. His excellent pass for the first goal in the semi final match against Germany is still remembered among football experts. After the tournament, he retired from international football. In altogether 46 matches he scored six goals.