Karl-Heinz Schnellinger started his career at a very young age in the Duren 99 team. Then after having played in various national juvenile teams, on April 2nd, 1958 he made his debut in the German National Team playing against Czechoslovakia  in Prague. He played two matches during the FIFA World Cup in Sweden which was the first of his four World Cup championships.

At the same time he was  transferred to the Cologne team winning the  title of German Champion in the  1961-1962 season. Immediately after he flew to Chile with the German National Team  and  played up to the quarter finals loosing against Yugoslavia. In 1962 he became the German Player of the Year and the Cologne Athlete Number One. In the summer of 1963 he moved for a three year deal to Italy playing one season with the  Mantua team, one with Rome and then he was acquired by AC Milan playing there nine seasons, winning four Italian Cups, two Cup Winners’ Cups, one Italian Championship title and one Intercontinental Cup. He played also the FIFA World Cup in England in 1966 and in Mexico in 1970 gaining respectively a second and third place