Aim: This study aimed to investigate the protective effect of anastrozole on experimental varicocele -induced testicular dysfunction in rats. Material and method: adult male albino rats were divided randomly into three groups; group 1 act as control. In group 2 (varicocele rats) varicocele was induced by partial ligation of the left renal vein. Group 3 (anastrozole-treated group) varicocele rats received anastrozole (400mg/l) in the drinking water for a period of 9 weeks immediately after ligation of the left renal vein. Serum FSH, LH, testosterone and intratesticular testosterone were measured. Seminal parameters (progressive motility, sperm cell concentration, epididymal sperm abnormal forms) were estimated. Testicular tissue specimens were histopathologically examined by hematoxylin & eosin staining. Results :after 9 weeks of operation, the varicocele induced significant decreased of bilateral intratesticular testosterone levels and marked impairment of seminal parameters and histopathological changes in the rat tests compared with control group (p