Muñoz was a regular player for Spain for most of the 1980s, receiving his first opportunity on 25 March 1981 in a 2–1 friendly win with England and going on to earn a further 59 caps, with three goals. He played for the nation at the 1986 FIFA World Cup as well as the UEFA Euro 1984 (in a final runner-up position, to hosts France) and 1988 tournaments, retiring from international duty immediately after that group stage exit.