Background and Aims: The present study was carried out to examine the predictive value of endocrine profiles as indicators of the sperm retrieval rate on testicular sperm extraction (TESE) in azoospermic men. Methods: Prior to TESE, the serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, testosterone, dihydrotestosterone (DHT), estradiol and 17α-hydroxyprogesterone were measured and the sagittal cross-sections of the testis were acquired using ultrasonography. Results: The sperm retrieval rates according to the cause of azoospermia were 40% for idiopathic azoospermia, and 100% for obstructive azoospermia, cryptorchidsm and ejaculatory disorder. Based on the endocrinological profiles, the sperm retrieval rates showed significant differences at 100% for FSH 15mIU/mL or LH2mIU/mL, 0% for FSH>60mIU/mL or LH>12mIU/mL, and 33% for the intermediate groups (P< 0.01). Comparison of the retrieval of spermatozoa and serum DHT level for the intermediate group also showed a significant difference, with retrieval rates of 58% for DHT0.5ng/mL and 0% for DHT > 0.5ng/mL (P<0.01). Conclusions: The etiology, serum FSH, LH and DHT levels are useful in predicting the sperm retrieval rates on TESE in azoospermic patients. (Reprod Med Biol 2005; 4: 239-245).