Approximately 2.4 million couples in the United States suffer infertility, representing 10-15% of the reproductive age cohabitants. Abnormalities in the male partner are the sole or a contributing cause in 40-50% of cases; and although there are rare patients who will be diagnosed with specific treatable abnormalities, the majority will be found to have idiopathic oligozoospermia. The treatment of male infertility by conventional methodologies has been frustrated by a general lack of success, and many medical and surgical innovations have met with equivocal results or outright failure. In contrast, in vitro fertilization and the related areas of micro assisted fertilization have obtained significant success and show promise of revolutionizing the treatment of the infertile mate. Fertilization potential can be enhanced greatly by in vitro insemination using techniques that increase the density and motility of the inseminating sperm. When fertilization in vitro fails, microsurgical techniques can be used to assist fertilization by directly placing sperm into the oocyte, Through IVF and micro assisted fertilization, pregnancies seem possible even in the presence of the most extreme semen abnormalities.