Long-term post-treatment gonadal toxicity was examined (median 3 years after treatment discontinuation) in 125 testicular cancer patients treated with standard regimens: no radiotherapy or chemotherapy (36 patients), infradiaphragmatic radiotherapy (38 patients), and 3-4 cycles of cisplatin-based chemotherapy (51 patients). Radiotherapy and chemotherapy had no impact on serum testosterone, but led to a slight increase in serum follicle-stimulating hormone (FSH). The lowest median value of post-treatment sperm cell count was observed after infradiaphragmatic radiotherapy, the highest value after standard chemotherapy. After more intensive cytotoxic treatment recovery of the gonadal function seemed to be delayed. In testicular cancer long-term post-treatment gonadal toxicity is correlated to the patient's pretreatment gonadal function and age rather than to the standard treatment of the malignancy. In patients with pretreatment normal gonadal function the risk of permanent treatment-induced toxicity is minimal after present standard treatment.