For several years, fertility disorders have been on the increase worldwide. These disorders affect both sexes, but are more pronounced in men; and in half of cases the etiology is unknown. The role of drugs in male infertility has been little studied to date. Most of the available data comes from experimental animal studies, with all their limitations. With the exception of a few drugs, such as certain anticancer agents, human data are rare. This article describes the mainly drugs known to have deleterious effects on male fertility, the mechanisms leading to these effects and methods used to assess the risk of drug-induced male infertility. It underlines the need for further work in experimental research, clinical trials and post-marketing surveillance to improve our knowledge of drugs that induce male infertility. Although these adverse effects are not life-threatening, they can have a significant impact on patients’ lives.