"Crack" cocaine abuse often produces severe cocaine dependence that is refractory to available pharmacological and outpatient psychotherapeutic treatments. We conducted two preliminary investigations evaluating the efficacy of flupenthixol decanoate, a depot xanthene requiring infrequent intramuscular administration, in the treatment of cocaine withdrawal. Ten outpatient crack cocaine smokers with poor prognoses were administered flupenthixol decanoate in an open-label, open-ended trial. Flupenthixol decanoate was well tolerated and appeared to decrease cocaine craving and use markedly and rapidly, producing a 260% increase in the average time retained in treatment among these subjects. These promising but preliminary data, combined with the magnitude of problems presented by crack, warrant rapid, expanded double-blind assessment of flupenthixol decanoate in cocaine-abuse treatment.