The advent of large-scale, population genetic databases (PGDs) in several countries around the world marks a significant development in human DNA banking and genetic research. The European countries that have led the way in the development of PGDs are Iceland, Sweden, Estonia and the U.K. In legal terms, the emergence of PGDs has been far from straightforward as such projects pose a range of difficult and complex issues for the law to address. This article canvasses the current law in Iceland, Estonia, Sweden and the U.K. on four fundamental issues of principle pertaining to PGDs, in order to illustrate the difficulties that have emerged around PGDs, highlight key areas of legal concern, and shed light on possible ways forward. It compares and contrasts the differing legal positions and lawmakers' responses to date in these four European countries that have established PGDs or are seeking to do so. The four fundamental issues examined are: (1) consent, especially for secondary research purposes; (2) ownership of biological samples, data and databases; (3) the rights of certain third parties to gain access to, and to use, PGD biological samples and data; and (4) benefit sharing, including the provision of feedback and genetic counselling to participants. This analysis may offer some guidance for policymakers in other jurisdictions where PGDs have been proposed or are being established.