['We evaluated clinical characteristics, sperm retrieval rates, and birth rates in a relatively large number of infertile patients with Y chromosome microdeletions.', 'We retrospectively reviewed clinical data from 213 patients with nonobstructive azoospermia (NOA) and 76 patients with oligoasthenoteratozoospermia (OATS) who were tested for Y chromosome microdeletion from March 2004 to June 2011.', 'Of the 289 patients, 110 patients presented with Y chromosome microdeletion and 179 patients presented with no microdeletion. Among the patients with Y chromosome microdeletions, 83/110 (75.4%) were NOA patients and 27/110 (24.5%) were OATS patients. After subdividing the patients with Y chromosome microdeletion, 29 had azoospermia factor (AZF)b-c microdeletion and 81 had AZFc microdeletion. The sperm retrieval rate was similar between patients with Y chromosome microdeletion and those with no microdeletion (26.6% vs. 25.6%, p=0.298) after multiple testicular sperm extraction (TESE). Excluding 53 patients who did not undergo TESE, 30 patients were analyzed. All of the 9 men with AZFb-c microdeletion had a complete absence of sperm despite multiple TESE. However, multiple TESE was successful for 9 of 21 patients with only AZFc microdeletion (p=0.041). Twenty patients with Y chromosome microdeletion gave birth.'] Is detection of Y Chromosome Microdeletion Valuable in the Treatment of Patients With Nonobstructive Azoospermia and Oligoasthenoteratozoospermia : Sperm Retrieval Rate and Birth Rate?