The initial evaluation of the infertile man includes a diligent search for testicular factors, gonadotoxins, and coital factors so as to identify existing causes of impaired fertility and to prevent further dimunition in fertility. There are also prophylactic measures in the treatment of all men that can prevent future infertility, such as prompt correction of cryptorchidism, testicular torsion, genital infection, and adolescent varicocele and proper precautions to limit occupational, medical, and recreational gonadotoxins.