A phase II trial of vinblastine in patients with refractory epithelial ovarian adenocarcinoma of the ovary was conducted by the Gynecologic Oncology Group (GOG) between March 9, 1988 and July 7, 1988. Vinblastine was administered in a dose of 9 mg/m2 intravenously every three weeks until disease progression or toxicity supervened. Twenty patients were entered initially. One was ineligible due to a previous primary cancer. Thus, 19 patients are evaluable for toxicity and response. All patients had cisplatin-combination chemotherapy and four had prior radiotherapy. Median age was 63 years (range 40-75 years). Thirteen patients had disease in the pelvis and six had extrapelvic metastases. Ten patients had grade 3 lesions and seven had grade 2. A median of two courses (range: 1-6) were administered. Toxicity was moderate. Seven patients (36.8%) experienced GOG grade 3 or 4 leukocytopenia and six had grade 3 or 4 granulocytopenia. Median nadir WBC was 2,000 cells/microliters (range 600-3,500) and platelet nadirs for the three patients with thrombocytopenia were 60,000, 116,000, and 147,000. Other toxicity included grade 3 gastrointestinal and renal toxicity in one patient each. Seven patients (36.8%) had stable disease on therapy and 12 had increasing disease. No responses were observed. Vinblastine in this dose and schedule is inactive in patients with resistant epithelial ovarian adenocarcinoma progressing on first-line chemotherapy.