Biennials have been central to the development of contemporary art for decades, but there is a paucity of published material specifically related to this subject. Documentation for these important exhibitions is not always made available and it is often difficult to acquire, posing an obstacle to current and future research across a number of areas within contemporary art, curating and art history. This article offers an overview of major current biennials and of the different sources of information they produce (catalogues, other printed material, online resources, archives), and surveys the secondary literature of the phenomenon. It also discusses specific collection development issues in libraries, from a research perspective, proposing a set of recommendations for best practice.