The inscription of East Rennell in Solomon Islands on the World Heritage List was a landmark in the implementation of the World Heritage Convention. However, the site is now on the List of World Heritage in Danger, threatened by resource development, invasive species, climate change and the over-harvesting of certain animals. This article examines the scope for the Protected Areas Act of 2010 to be used to safeguard the site, and the challenges that may be encountered if the Act is implemented there. It explains how the Act provides direct protection against some (but not all) of the threats to East Rennell. Furthermore, the approach to conservation facilitated by the Act is appropriate for Solomon Islands, where most land is under customary tenure, many people rely on natural resources to support their subsistence lifestyles and the government's capacity to enforce legislation is limited. The article argues that the relationship between the legislation and custom must be considered in the design of the landowner consent process, the preparation of the site's management plan, and the selection of its management committee. Additionally, the protected area should aim to improve the livelihoods of the East Rennellese, as well as safeguarding the site's heritage values.