The objectives of the study conducted at the Arignar Anna Zoological Park, Chennai, Tamil Nadu, were to assess the success of captive breeding of chosen mammalian species and to evaluate the potential of the zoo for ex situ conservation. Results obtained showed that the potential of the zoo to conserve those species threatened in the wild, is enormous. This was evident from the records of successful captive births of the four selected mammalian species, (Cervus eldi eldi, Macaca silenus, Panthera tigris and Trachypithecus johnii). Selection was based on: IUCN Red List status of the species, inclusion of representatives of important orders and distribution of the species in the country. Results show that zoos in India concentrate largely either on those species which are at a lower risk of extinction in the wild or on large bodied mammals like Panthera tigris, which are difficult to reintroduce into the wild. This is not in accordance with the IUCN Policy Statement on captive breeding. There are lacunae in the areas of prioritisation of Indian taxa for conservation breeding and in the formulation of zoo policy. This has consequently restricted, in many ways, the extent of zoo contribution to the conservation cause. Recommendations have been suggested based on the results that can improve the potential of the zoo to perform its multifaceted role. These include: * recognising the importance of enclosure enrichment in stimulating physiological and psychological development, which are essential in reintroducing animals to their natural environment * immediate formulation of a zoo policy * prioritisation of Indian taxa for conservation breeding * more attention on smaller bodied mammals like the rodents and bats, which are easier to reintroduce without compromising on visitor appeal * a re-evaluation of the zoos raison d’etre