Concepts regarding the evaluation and management of the infertile male have evolved during the past decade primarily because of the development of new methodology. Nevertheless, the causes of male infertility is often obscure, and the clearly defined causes are infrequent or rare. Many published reports show that about 40 per cent of the fertility problems among childless couples are attributable to the male, 40 per cent may be attributed to the female, and in 20 per cent, both partners are responsible. Most patients who present for evaluation and treatment have at least one year history of infertility. In addition to complete history and physical examination, semen specimens are collected and examined. If this is completely, it is reasonable to proceed with an investigation of the woman. If the semen analysis shows an abnomality, further studies should be made of the man. A thorough evaluation is essential before any decision can be made about treatment of the men suspected of being infertile. This evalution should include hormone measurements, karyotype, testicular biopsy, and other procedures in addition to semen analysis. The effectiveness of medical treatment of the subfertile male is dependent upon the severity of seminal abnormalities and the underlying cause. Defining the correct diagnosis is therefore indicated, since specific and effective surgical or medical treatment is available for many of these disorders. On the other hand, seminal abnormalities exist in many men for whom no precise can be determined. Treatment of these idiopathic cases is empirical and less satisfactory. In cases of hypothalamic-pituitary problem, the continuous use of human menopausal gonadotropin and human chorionic gonadotropin may be required. Medical therapy is also indicated in the rare patient who has an adequate sperm concentration but a motility index of less than 120; these patients may respond to administration of low dose of testosterone in the form of Halotestin. High protein, low fat diets, vitamin E, folic acid, vitamin A, thyroid extract, and arginine have not been found to be advantageous in the treatment of idiopathic oligospermia. Conflicting reports exits regarding the efficacy of other forms of nonspecific therapy for patients with idiopathic oligospermia. The various therapeutics recommended include; clomiphene citrate; human chorionic gonadotropin; and/or testosterone rebound therapy.