Background: Many biobanks have struggled to deliver on the high expectations and claims made for them because of insufficient samples, inadequate infrastructure, cost of establishing and maintaining a large enough resource over the long term, and satisfying legal, ethics and governance requirements. Increasingly, networks have formed to help with the collection, processing, storage, advertising, and distribution of samples. However, there are also challenges to establishing and maintaining biobank networks. Aim: To classify biobanks in order to better understand the problems faced by biobank networking. Methods: Interviews were conducted with principal investigators and/or managers responsible for 33 biobanks in 9 countries. Results: Biobanks were classified into the following categories: ‘storage’, ‘bring-and-share’, ‘catalogue’, ‘partnership’, ‘contribution’ and ‘expertise’. Conclusion: It was possible to allocate all of the biobanks visited to one of the network categories although some fitted better than others. Thus, the classification may not be mutually exclusive nor encompass all types of biobanks. Many of the governance and operational problems associated with the biobanks visited were due to networking functions: either intra- or inter-biobank networks. Thus, this proposed classification system should help better understand these issues and identify solutions.