Abstract The role of ex situ activities for the conservation of biodiversity, and of zoos and aquaria in particular, is open to continuing debate. The present note highlights the conservation breeding potential of zoological gardens and aquaria in the European union, but it also recognises the lack of a convincing scientific and legal framework that encourages ex situ activities for 'exotic' species. If ex situ programmes are considered essential for global biodiversity conservation, the EU should not limit itself to regulating zoos through the zoo directive, but should actively promote and support their ex situ conservation activities