Objective: This study was designed to evaluate the effect of letrozole 2.5 mg, an aromatase inhibitor, on the sperm retrieval rate (SRR) by the testicular sperm extraction (TESE) procedures that was done for the treatment of males with non-obstructive azoospermia (NOA).Materials and methods: Data was collected retrospectively from males diagnosed with non-obstructive azoospermia who underwent TESE procedure in the duration between May 2010 until June, 2018. The collected data includes the age of the patient, body mass index (BMI), testicular volume, hormonal profile (FSH LH, prolactin, testosterone), and the use of letrozole preoperatively. Logistic regression was done to address the association of these parameters to the sperm’s retrieval rate.Results: The study screaned 145 patients. Eighty patients fit the inclusion criteria and thus they were statistically analyzed. The use of letrozole was associated with negative TESE outcome (p=0.006), odd (0.154) CI 0.04-0.579. The other factors had no significant correlation to the TESE results.Conclusion: The evidence in this study showed an adverse effect of letrozole use on TESE results of those with high FSH.