Conclusions: Prevalence of Y chromosome microdeletions in infertile Chilean men is similar to the prevalence presented in international studies. As AZFa and AZFb mutations are associated with complete absence of viable gametes, and AZFc has important consequences in the fertility potential of the offspring, these mutations have to be searched when presented with an infertile patient with severe sperm alterations. (C) 2015 Asociacion Espanola de Andrologia, Medicina Sexual y Reproductiva. Published by Elsevier Espana, S.L.U. All rights reserved.