The authors administered fluoxetine to 11 cocaine-abusing heroin addicts entered in a methadone maintenance program to determine whether it would decrease cocaine craving and use. Three patients discontinued treatment within a few days of initiation because of lack of any acute therapeutic effect. The remaining 8 received fluoxetine for at least 1 week and were followed up over 1 to 6 months. Of these 8, 5 (63%) were successfully treated for cocaine abuse. Three case examples are presented. Fluoxetine may prove a useful addition to the therapeutic armamentarium in the treatment of cocaine abuse.