Infertility affects 15 percent of couples, and 50 percent of male infertility is potentially correctable. Evaluation of the subfertile man requires a complete medical history, physical examination, and laboratory studies. The main purpose of the male evaluation is to identify and treat correctable causes of subfertility. In addition, many men seek an explanation for their condition, which can be discovered during their evaluation. Furthermore, the male fertility evaluation can uncover significant medical and genetic pathology that could affect the patient's health or that of his offspring. Although pregnancies can be achieved without any evaluation other than a semen analysis, this test alone is insufficient to adequately evaluate the male patient. Treatment of correctable male-factor pathology is cost effective, does not increase the risk of multiple births, and can spare the woman invasive procedures and potential complications associated with assisted reproductive technologies. Appropriate evaluation and treatment of the subfertile man are critical in delivering suitable care to the infertile couple.