Captive-breeding programmes are important components of conservation strategies for rhinoceros. Rhinoceros in zoos can serve as (1) genetic and demographic reservoirs to reinforce wild populations as the need and opportunity occur, and (2) ambassadors to increase public awareness and support, especially financial, for conservation of wild populations. However, for these functions, rhinoceros in captivity must be managed scientifically and co-operatively to produce viable populations. Population-management programmes for Black rhinoceros Diceros bicornis, White rhinoceros Ceratotherium simum and Indian rhinoceros Rhinoceros unicornis are operating in various regions of the zoo world, especially North America [Species Survival Plans (SSP)] and Europe [European Endangered Species Programmes (EEP)]. Analyses indicate that rhinoceros populations in captivity are achieving variable levels of viability. In SSP and EEP populations Black rhinoceros and White rhinoceros are genetically but not demographically satisfactory, while Indian rhinoceros is healthy demographically but limited genetically. Improvement is needed and could be achieved through better management.