More than 50% of patients with non Hodgkin's lymphomas (NHL) are long-term survivors. We have retrospectively analysed the indication of semen cryopreservation and late gonadal toxicity for 213 males patients consecutively treated at the Gustave Roussy institute from 1980 to 1993 for NHL. The mean age was 30 years (15-42) and all patients received chemotherapy with or without radiotherapy. Initial spermograms and cryopreservation of semen were obtained in only 24 patients (half of them between 1991 and 1993). Spermogram characteristics were as follows: 11 normal; 13 abnormal with oligospermia (n = 7), asthenospermia (n = 7), and teratospermia (n = 8). No relation was found between the pretherapeutic status and the semen sample quality. Cryopreservation was possible in only 22 cases, and among the 16 surviving patients, two have undergone insemination and the remaining 14 are maintaining their cryopreserved semen samples. Long-term gonadal toxicity was assessed on spermograms of nine patients: three of whom had evidence of return to pretherapeutic status. FSH levels were assayed for 48 patients: at a threshold of 8 g/m2 of cyclophosphamide, 86% of patients had elevated values (P < 10(-6). Cumulated doxorubicin doses were not correlated with FSH elevation. Five patients have had children after treatment. In conclusion, chemotherapy for NHL seems to induce an intermediate level of gonadal toxicity which is between that of MOPP and ABVD. Complete information about gonadal toxicity of chemotherapy is warranted for young male patients who are to receive chemotherapy and semen cryopreservation should be suggested to this population.