Nogitecan hydrochloride(topotecan)has shown efficacy in patients with recurrent ovarian cancer, but has not been used widely in Japan. We evaluated the efficacy and adverse effects of topotecan in 12 patients (median age, 62 years) treated for recurrent ovarian cancer between 2000 and 2013. Four patients had relapsed after primary treatment, and 8 had relapsed at least twice. Seven patients had been treated with more than 3 prior regimens. Initial treatment of the 12 patients consisted of intravenous topotecan (1.0-1.4 mg/m2/day) for 5 consecutive days. Initial doses were based on previous chemotherapy and/ or renal function, with reduced doses administered to patients with severe adverse effects during prior courses of treatment. The 12 patients received a total of 54 courses of topotecan(range, 1-15 courses). Of these 12 patients, one achieved a partial response and 6 had stable disease. The median time to progression was 14.4 weeks. All 12 patients had grade 3-4 myelosuppression, while none had febrile neutropenia or severe non-hematologic toxicities. Patients who received higher doses or increased courses of chemotherapy had apparently more severe adverse events. These findings suggested that topotecan should be used as a second- or third-line treatment, rather than later, in patients with tumor recurrence, with its dose reduced according to the physical status of each patient. Such strategies may enhance both the efficacy and safety of topotecan in patients with recurrent ovarian cancer.