Thirty-one patients were treated with cisplatin combination chemotherapy for advanced seminoma (26 Stage III or bulky Stage II testicular, and five disseminated extragonadal). Seventeen (89%) of 19 patients not previously pretreated and four (80%) of five who had received only abdominal irradiation entered continuous complete remission (CR), versus only two (28%) of seven patients who had received extensive infra- and supradiaphragmatic radiotherapy. Results were not significantly influenced by stage, human chorionic gonadotropin (HCG) titers and histologic subgroups, whereas patients with lactic dehydrogenase (LDH) values exceeding 500 mIU/ml did worse (50% continuous CR rate in 12 cases) than those with normal or less elevated titers (89% continuous CR rate in 19 cases). After a median follow-up period of 34 months (range, 12+ to 77+ months), 23 patients (74.5%) remain alive in continuous CR, two (6%) died in CR and another one (3%) entered CR after deferred treatment of residual disease. Five patients (16%) died of cancer. Toxicity was severe in extensively irradiated patients, but it was acceptable in those not pretreated and in those who had received only subdiaphragmatic radiotherapy. Cisplatin combination chemotherapy can be successfully and safely used as the primary treatment of choice in patients with advanced seminoma. It is also an excellent salvage therapy for patients who had received subdiaphragmatic irradiation only. On the contrary, it is very difficult to treat with chemotherapy extensively irradiated patients.