A spermogram was performed before treatment in 57 young patients with Hodgkin's disease. The mean results were normal, and similar to those reported in fertile populations. Nineteen patients had an abnormal spermogram; 12 of these men had had fever recently or were febrile at the time of the exam. When the temperature was below 38.5°C, there was only asthenospermia. With a higher temperature, semen anomalies were more severe, with oligoasthenospermia or even azoospermia. Only five febrile men had a normal spermogram, and all had slight fevers. Therefore, semen anomalies noted in about one third of patients with Hodgkin's disease are probably not due to a disease specific gonadal alteration, but can be attributed to fever which gonadal effects have been recognized for a long time and are well-documented.