The Pacific region is a biodiversity hot spot with a long history of human occupation closely linked with sustainable use of the marine environment. The health of the marine environment and its resources is of environmental, economic and socio-cultural concern, and law plays an important part in its conservation and management. Designing appropriate legal mechanisms is, however, a challenging prospect. The Pacific Island countries involve a complex environment for law and policy-makers. As a result of their colonial past, these nations are legally pluralist, with more than one legal system operating at the same time. In addition, Pacific Island countries have embraced international law, ratifying the majority of key environmental treaties and subsequently taking steps to implement their obligations, including those related to biodiversity conservation. This complicated legal landscape means that law and policy must be adopted that implements international treaties whilst also meeting the needs of local communities. A particular feature of the Pacific region is the widespread adoption of community-based marine management approaches. Their proliferation is due to a combination of underlying customary law, which has subsisted despite colonial rule, together with a willingness by governments to support local approaches. This article examines community-based marine management through a legal lens; it commences by outlining traditional rules for marine management before exploring the contemporary legal position with a focus on the hybridisation of state-based legislation and customary law. Finally, comments are made on the effectiveness of these legal approaches, as well as remaining challenges.