Approximately 10% of male factor infertility is caused by azoospermia, and nearly two thirds of these patients have nonobstructive azoospermia (NOA). Before intracytoplasmic sperm injection (ICSI), they were hopeless, but nowadays with the advent and improvement in ICSI, these men have the opportunity of using in vitro fertilization (IVF). As experience has been gained, increasing numbers of men who have NOA are having sperm retrieved from their testes and used for ICSI/IVF. Although various degrees of NOA, from Sertoli cell–only syndrome to hypospermatogenesis, can be treated in this fashion, it seems that the more advanced the spermatogenesis on diagnostic biopsy, the greater is the chance of recovering mature sperm.This article reviews the various sperm retrieval techniques, discussing the advantages and disadvantages and the outcomes of each. Predictive factors for sperm retrieval are presented, as are some of the controversies that exist regarding sperm Acquisition in NOA.