Objective: This study was undertaken to determine the prevalence of Y-chromosome microdeletions in couples with recurrent pregnancy loss (RPL) as compared with fertile couples. Study Design: Forty-three men from couples with recurrent pregnancy loss, and 43 men from couples with a live birth and no history of miscarriages were recruited from Zekai Tahir Burak Woman Health, Education and Research Hospital. The DNA was tested for the presence of 4 sequence tagged sites (STSs) spanning 4 AZF regions: DYS220 (AZFb), DYS235, DYS236, and DYS237 (AZFd). Results: Seven (7) of the 43 men (16%) from couples with recurrent pregnancy loss had microdeletions in 1 or more of the 4 segments studied, whereas none of the fertile men had any microdeletions (P < .05). Their microdeletions were all found specifically at locus DYS 220 (AZFb). Conclusion: The prevalence of the Y chromosome microdeletion in AZF region was much higher in men from couples with recurrent pregnancy loss than men in fertile couples. This study showed that Y chromosome microdeletion in AZF region may be a possible etiologic factor of recurrent pregnancy loss. © 2008 Mosby, Inc. All rights reserved.