Riedle made his debut for West Germany on 31 August 1988, playing 15 minutes against Finland and scoring in a 4–0 away win for the 1990 FIFA World Cup qualifiers. Selected by coach Franz Beckenbauer for the finals in Italy as a backup to Klinsmann and Rudi Völler, he contributed with four games as the national team won its third title, starting once due to suspension to the latter. In the semi-final against England Völler limped off injured in the first half and Riedle came on as a substitute. The match went to penalties and Riedle converted his attempt as Germany eventually prevailed. However Völler recovered to start the final and Riedle remained on the bench.