Under the biological species concept, the intraspecific variability and true species richness of Palearctic mammals has often been overlooked, and therefore the need to conserve it. Recovery projects of endangered European mammals in Western Europe rely mainly upon translocation of conspecifics from viable populations in Central or Eastern Europe. From a wildlife management and restoration ecology point of view, many such recovery projects have been successful. However, from a biodiversity perspective it could be argued that they could have failed to protect the original European biodiversity. The increasing evidence of a complex phylogeographic pattern in many European mammals – especially in the Mediterranean region – has led to a reconsideration of the conservation unit and highlights the need for species-specific programmes for assuring the survival of threa- tened, distinctive populations. Such programs should also include captive breeding. It is the- refore suggested that a two-level classification of captive breeding programmes is needed according to the degree of threat of concerned taxa, to maximise available resources without jeopardising in situ conservation. It is proposed to distinguish between a) level I captive breeding programmes, which are part of the conservation strategy for seriously threatened taxa and need to be financed by state or federal agencies, and b) “prophylactic” level II for vulnerable taxa or populations, and for which funds may be available mainly from the pri- vate sector. Available evidence suggests that given adequate husbandry techniques and pre- release training, even captive-bred carnivores can be successfully reintroduced to the wild. However, a closer collaboration among zoological gardens, zoologists and agencies invol- ved in wildlife conservation is needed to avoid ill-conceived, potentially dangerous captive- breeding and re-introduction projects.