Despite extensive research into the toxicity of bisphenol A (BPA), no report of its effect on erectile function exists. We performed this study to investigate the effect of BPA on erectile function. New Zealand white rabbits were treated intraperitoneally with 150 mg=kg of BPA every other day for 12 days (cumulative dose of 900 mg=kg). Four and 8 weeks after administration of BPA, the contractions and relaxation of cavernosal tissue strips were significantly suppressed in the BPAtreated animals compared to the control animals. Histologically, thickening of tunica albuginea, subtunical deposition of fat and decreased sinusoidal space with consequent increase of trabecular smooth muscle content were observed in the BPA-treated animals. These results suggest that xenoestrogen BPA may affect the erectile function through evident histological changes of the penis.