Twenty-seven fully evaluable patients with advanced ovarian cancer and documented disease progression despite cytotoxic treatment were treated with mitozolomide (NCS-353451) 90 mg/m2 as a 1-h infusion once every 6 weeks. None of the patients responded, one had stabilization of disease for 4 months. Haematologic toxicity was the major side effect with a nadir or white blood cell counts around day 40. Two patients died with severe leukopenia and septic shock. We conclude that mitozolomide is not active in this poor-risk group of patients.