Introduction: Testicular sperm extraction (TESE) has been widely used as a sperm extraction surgery for azoospermia even for obstructive azoospermia (OA) because it does not require surgical skill. However, there are postoperative pain issues, and subsequent testicular atrophy and decreased testosterone levels may occur with TESE. This study examines the usefulness of microscopic epididymal sperm aspiration (MESA) for OA.Methods: We studied 108 patients diagnosed with OA and treated with MESA at our institute between April 2004 and December 2021. The MESA was performed using a micropipette with a micropuncture technique under an operative microscope. When no sperm were present or motility was not observed, additional punctures to the epididymal tubule were performed.Results: Motile sperm were recovered in all cases (108 cases). Of these, intracytoplasmic sperm injection (ICSI) using frozen-thawed sperm was performed in 101 cases and the normal fertilization rate was 76.2%. A total of 436 embryo transfer (ET) cycles were performed. The implantation rate per transfer cycle was 47.9%, the clinical pregnancy rate was 41.0%, and the live birth rate was 23.7%. The per-case live birth rate was 84.8%.Conclusions: MESA-ICSI has a very good fertilization rate, clinical pregnancy rate, and delivery rate. Furthermore, the patient's postoperative pain is less, the number of sperm collected is larger, the burden on the embryologist who processes the collected sperm is less, and ICSI can be easily attempted after frozen-thawed sperm. MESA rather than TESE should be employed for the OA subjects.