Abstract: Cadmium induces cellular damage in reproductive system. We investigated vascular endothelial cellular injury induced by cadmium on blood vessels of the testis. Here we compared the fine structure of cellular changes in two groups of mice (SWR), experimental and control. The experimental group underwent cadmium ingestion at 1 mg.kg-1 daily for 4 weeks. The control group underwent ingestion of distilled water with equal dosages, using the same type of injectors, for 4-weeks. After cadmium exposure period both control and experimental groups were sacrificed and samples of the testis were processed for microscopic examination. The prepared samples were cut, stained and examined by Transmission Electron Microscope (JEOL-100 CX) at 80 KV. Ultrastructure examination revealed narrowing the lumen of the blood vessel associated with nuclear hypertrophy of the endothelial cells, irregular thickness of the endothelial cell cytoplasm. The endothelial cellular injury was associated with numerous pathological signs in germinal cell differentiation, heterogeneous chromatin distribution, irregular nuclear envelope and acrosomal dislocation. Based on the results of this investigation it can be concluded that endothelial cellular injury mediate early testicular failure secondary to microcirculatory impairment.