A total of 16 consecutive patients (15 with ovarian cancer and 1 with unknown adenocarcinoma) were treated with a standard regimen including cisplatin and cyclophosphamide or with the same regimen in combination with reduced glutathione as potential protective agent against cisplatin nephrotoxicity, in a non-randomized study. Reduced glutathione (1500 mg/m2) was administered prior to each cisplatin administration (90 mg/m2) to seven patients for a maximum of five consecutive courses. A standard hydration protocol without diuretics was used. The patients received a total of 33 courses with glutathione. Glutathione was well tolerated, since it did not produce appreciable side effects. Cisplatin and glutathione combination did not produce unexpected toxicity. Two patients treated with standard regimen without glutathione developed a transient nephrotoxicity. The severity of myelosuppression was reduced following glutathione administration. Moreover, the therapeutic efficacy was not impaired by glutathione pretreatment.