Because schizophrenic patients have a lifetime prevalence rate for cocaine abuse between 15 and 50 percent, the use of adjunctive pharmacotherapy should be considered in cocaine-abuse treatment programs. This 12-week, open-label outpatient study compares 12 cocaine-abusing schizophrenic patients treated with desipramine (DMI) 100 to 150 mg and antipsychotic agents to 15 patients treated with only antipsychotic agents (no DMI). All 27 patients participated in a Dual Diagnosis Relapse Prevention (DDRP) program, which integrates traditional substance-abuse relapse prevention and psychiatric social skills training. The DMI group was more likely to complete the study (83% vs. 60%, odds ratio = 3.3, NS) and had fewer cocaine-positive urines during the last 6 weeks (20% vs. 50%, odds ratio = 4.0, p < .01). In the context of a specialized dual diagnosis treatment program, patients receiving DMI substantially decreased cocaine usage and had improved psychiatric symptoms.