Depo-Provera (depot-medroxyprogesterone acetate or DMPA), administered either subcutaneously or intramuscularly, has undergone a thorough toxicological evaluation in a number of animal species. DMPA has been tested in short- and long-term toxicity studies in rodents, rabbits, and monkeys. It has been examined for its effects on reproduction in mice, rats, and rabbits, and for carcinogenic potential in rats, mice, beagle dogs, and rhesus monkeys. Genotoxicity tests have been performed in vitro and in vivo. This paper describes the toxicology data submitted to the US FDA in support of the New Drug Application (NDA) for Depo-Provera as well as data published in the literature. When interpreted in the light of the available pharmacokinetic information, these data demonstrate that DMPA is not significantly different from other contraceptive progestogens in its toxic and tumorigenic potential.