Continuous 24-hr infusion of ifosfamide (IFX) with mesna was studied in 19 patients with advanced epithelial ovarian cancer refractory to or recurrent after platinum-containing chemotherapy. The patients received IFX 5 g/m2 as a 24-hr i.v. infusion. Mesna (total dose 8 g/m2) was given i.v. 3 hr before, together with, and 0 and 6 hr after IFX infusion, respectively. Cytotoxic therapy was repeated every 4 weeks. Of 19 evaluable patients, none achieved a complete response, 2 showed a partial response, and 8 had stable disease. Median survival for all patients was 6 months, and median time to progression was 4 months. Toxicity was moderate. Leucopenia WHO grade III-IV was observed in 3 patients. Thrombocytopenia WHO grade III-IV was not observed. Nausea/vomiting WHO grade III-IV occurred in 8 patients. One patient experienced mild reversible confusion. No patients had macro-or microscopic hematuria and there was no deterioration of renal function. We conclude that IFX given as a 24-hr infusion is moderately well tolerated, but has only limited activity in patients with ovarian cancer refractory to or relapsing after prior platinum-containing chemotherapy.