Population-based biobanks promise to be important resources for genetic research. However, the study of normal genomic variation across populations requires the collection of data and biological samples from individuals on a large scale. While international collaboration has become both a scientific and an ethical imperative, international sharing of data and samples poses many challenges. Significant variation persists among the legal and ethical norms governing population biobanks in different jurisdictions. Many of these norms do not clearly provide for international access. To illustrate these problems, we collected and compared applicable legislative instruments, as well as ethical guidelines issued by national, regional, and international bodies. In addition, harmonization is faced with important limitations and may not be sufficient to ensure effective international sharing. Population biobanks are therefore looking for new ways to promote sharing and improve interoperability. The formation of biobank networks and the development of common governance tools are two approaches that are setting the groundwork for international collaboration in genetic research.