Riedle returned to Germany in 1993 and joined Borussia Dortmund. He was a starter for most of his spell, often partnering Stéphane Chapuisat, but failed to reproduce his previous form, never scoring in double digits; he was however important in the conquest of the 1995 and 1996 national championships (13 goals combined) and, in the 1996–97 UEFA Champions League, netted twice against Juventus in the final for a 3–1 success.