The treatment of male factor infertility is a rapidly developing field. The introduction of microsurgical fertilization techniques allows assisted conception units to treat couples who previously would not have benefited from in-vitro fertilization techniques. However, these techniques are only used for the minority of subfertile men in andrological practice. Many subfertile men are still treated pharmacologically or by sperm selection methods to enhance sperm fertilizing ability. Numerous pharmacological compounds have been described that enhance sperm motility and thus, potentially, sperm fertilizing capacity. This paper attempts to review these compounds and assess their role in treatment of the subfertile male.