For over 25 years, the Reproductive Health Surveillance Program has collected, processed, evaluated, and archived reproductive tracts from nondomestic mammals submitted by zoos. The analysis of the data from this archive has been used to recognize lesions associated with exposure to certain contraceptives; but arguably more importantly, to also document naturally occurring lesions. The goals of this program are to enhance the reproductive management of captive and free-ranging species by providing information about the effects of various contraceptives and to provide basic information regarding the natural reproductive histories and naturally occurring lesions in male and female zoo animals.