The two South American ratites (Lesser Rhea, Pterocnemia pennata and Greater Rhea, Rhea americana) are categorised as ‘Near Threatened’ in the Red List of Threatened Species of the International Union for Conservation of Nature and Natural Resources, and are included in Appendices 1 and II of Convention on International Trade in Endangered Species of Wild Fauna and Flora. The wild populations of rheas are affected by human activities, such as illegal hunting and egg harvesting, and conversion of natural habitats into croplands. On the other hand, commercial farming of rheas has been expanding in the last two decades. Studies on farms have led to improved production, not only for commercialisation, but also for the release of individuals to the wild. Effectiveness of this latter strategy was confirmed by fieldwork and radio-telemetry. Molecular studies revealed that genetic variability of captive populations of Greater Rhea were similar to those of wild ones, and they do not show signs of inbreeding depression or differences in allele frequencies. Consequently, as natural populations of rheas continue to decline, farms will arguably serve as genetic reservoirs and provide a source of individuals for repopulation. Therefore captive breeding should be regarded as having high value as a conservation tool for native ratites.