A breeding programme for Yellow-breasted capuchin Cebus xanthosternos was initiated at the Rio de Janeiro Primate Centre [Centro de Primatologia do Rio de Janeiro (CPRJ)], Brazil, in 1980 when this monkey was considered highly threatened. In 1987, a field survey concluded that an urgent measure that should be taken to save the species was the expansion of the breeding programme at the CPRJ and the extension of the programme to other collections with expertise in breeding New World primates. Mulhouse Zoo, France, proposed that CPRJ should expand the breeding programme to Europe and that the participating zoos should be asked to fund in situ conservation. The breeding programme began in Europe in 1990 at Mulhouse Zoo. At the end of 2010, there were 140 Yellow-breasted capuchins at 21 European zoos. Since 2002, in situ conservation actions have provided important information about wild populations. The largest forest fragments, scattered across c. 470 000 km2 over Atlantic Forest, Cerrado and Caatinga, were visited, and wild groups were monitored in three of them. The findings from these studies help us to understand the basic ecology of this primate and to build a conservation action plan for the future.