The influence of cadmium on spermatogenesis in roe deer was studied, comparing animals from areas with high (n = 37) and low (n = 23) cadmium exposure. Testes were evaluated during pre-rut (May) and rut (July/August). During these periods the cadmium accumulation (mg/kg kidney) in polluted regions averaged 3.41 and 3.52 in comparison with 1.61 and 1.81 in controls. Cadmium accumulation was positively correlated with testis weight during both seasons. In May the proliferation (units of tissue polypeptid specific antigen/g parenchyma) was lower in animals with higher cadmium (24.02 compared with 78.20; P < 0.01). During the rut, testicular proliferation and spermatozoa/g testis as well as apoptosis showed no significant changes with increased cadmium contamination. The results suggest delayed proliferation during the pre-rutting period in animals with high cadmium exposure, but other indications of effects on the testis were not significant.