The mechanism and hemodynamics of penile veins in erection have long been a matter of controversy and hypotheses. With the intention to develop a new concept of venous ultrastructure in penile venous insufficiency, we studied the histopathology of 13 dorsal penile veins obtained from important patients during venous ligation because of proven venous leakage. Besides, 1 normal deep dorsal vein taken from a volunteer who underwent another type of penile operation was also examined. All sections were stained with hematoxylineosin, Gomori trichrome, periodic acid-Schiff, Gomori reticulum and Verhoeff elastic stains. All 13 veins showed some significant histological changes namely nodular hypertrophy in 7; nodular atrophy in 2, diffuse atrophy in 2, diffuse hypertrophy in 1 and minimal changes in 1. In general, the dominating histological appearance was hypertrophy of the muscular pattern and enhancement of collagenization. None of these alterations was prevalent in the normal control. The cause and the result relationship between venous leakage and the mentioned histological changes still remains a matter of debate.