Children of substance‐abusing parents (COS) are at risk for developing psychosocial problems. We evaluated the effectiveness of the manualized, 9‐session psycho‐educational preventive intervention “TRAMPOLINE” (PE) for 8–12‐year‐old COS compared with a non‐educational “fun and play” group (NE) of equal length delivered by social workers in 27 German counselling centres.