This study reports on the stagnation of blood within the microcirculatory vessels of the testes of patients with varicocele. Both fine structural and quantitative studies were carried out on testicular biopsies from 14 men with varicocele and a control group of three men. Arterioles, capillaries, and venules were completely filled with blood in all affected testes. Enlarged pores were also noticed between the endothelial cells of these affected vessels. Lumen diameters of the arterioles were significantly decreased in the affected testis compared to controls. No change in the overall diameter of the arterioles and venules was noted. Significant thickening of the limiting membrane was also noted in the affected testis. It was concluded that the stagnation of blood in the microcirculatory vessels may cause local hypoxia and ischemia, which lead to spermatogenic disorders.