A prospective phase II study was performed to evaluate the effect and tolerability of a peroral combination chemotherapy consisting of hexamethylmelamine, cyclophosphamide, and carmofur in patients with epithelial ovarian cancer previously heavily treated by cisplatin-based chemotherapy but no longer responding to it. Of the 27 patients 1 showed a clinical complete remission lasting 15+ months and 4 a partial remission of 6+ to 21 months. A further 7 patients had an unchanged situation of 4 to 13+ months. The median survival of the nonresponders was 3 months. The side effects were tolerable, mostly nausea and vomiting. Only 4 of 27 patients suffered from severe vomiting causing discontinuation of the therapy. The peroral ambulatory chemotherapy prolonged markedly the overall survival of about one-half of the patients with ovarian cancer who previously failed to respond to cisplatin-based chemotherapy.