BACKGROUND Patients with recurrent epithelial ovarian carcinoma who progress through a cisplatin-based regimen or recur less than 6 months after discontinuing cisplatin, have limited therapeutic options. The Gynecologic Oncology Group conducted a Phase II trial of merbarone in this patient population. METHODS Twenty-seven patients with recurrent epithelial ovarian carcinoma who had previously received one prior cisplatin-based regimen were scheduled to receive 1000 mg/m2 of merbarone by continuous intravenous infusion through a central line each day for five days every four weeks. RESULTS Of the 27 patients entered, one was ineligible because of wrong primary, and two never received the drug, leaving 24 patients evaluable for toxicity. Twenty of 24 were evaluable for response. The regimen was well tolerated with only one episode each of GOG grade 3 leukopenia (4%) or grade 4 granulocytopenia (4%). There was one episode (4%) of GOG grade 3 gastrointestinal toxicity. Prior to increasing the infusate concentration to 4 mg/ml, there was one episode (4%) of altered mental status which, in retrospect, may have been secondary to iatrogenic hyponatremia. There were two partial responses (10%) (95% confidence interval 1.2-31.7%). CONCLUSIONS Merbarone exhibited minimal activity at this schedule in this pretreated group of patients with epithelial ovarian carcinoma.