Non-obstructive azoospermia (NOA) poses significant challenges in male infertility management due to the absence of sperm in the ejaculate. Diagnostic strategies and treatment approaches for NOA vary among different guidelines, such as those provided by the American Urological Association/American Society for Reproductive Medicine (AUA/ASRM) and the European Association of Urology (EAU). This chapter reviews the diagnostic methods, treatment options, and recommendations for men with NOA according to the guidelines of these societies. Key points include the role of diagnostic tests such as testicular biopsy, the controversy surrounding varicocele repair in NOA, and the preference for microdissection testicular sperm extraction (microTESE) for sperm retrieval in surgical interventions. The introduction of this paper outlines the importance of guidelines from leading urological societies in guiding clinical practice for managing male infertility, particularly in cases of NOA.