Genetic factors including Y chromosome microdeletions and androgen receptor (AR) gene mutations are responsible for male infertility. In the present study, genetic analysis was performed in an infertile Iranian male with azoospermia. Multiplex polymerase chain reaction with 6 sequence-tagged site markers on the Yq11 chromosome revealed no microdeletions in the Y chromosome. Single-strand conformational polymorphism and sequencing analyses detected a 1510C→A transversion in exon 1 of the AR gene, which resulted in a p.Pro504Thr substitution in the transactivation domain of the protein. The present study suggested that mutations in the AR gene might be responsible for some cases of idiopathic infertility, and therefore, molecular analyses may be useful for genetic counseling of candidates with regard to the use of assisted reproductive techniques.