In the past, indigenous people have often been entirely excluded from social impact assessments (SIAs) of projects or activities that affect them, or have faced major financial and cultural barriers in participating effectively and in having their perspectives accepted as legitimate. More recently, indigenous groups have achieved greater success in influencing SIA, but a fundamental problem remains. Their enhanced input into SIA has generally not increased the capacity of indigenous people to shape the outcomes of development projects in ways that favor their interests. This problem reflects a wider failure, extensively documented in the literature, to integrate SIA into decision-making. Drawing on case studies from Australia's Cape York Peninsula, this article shows how SIA can be integrated into the negotiation of legally binding agreements between developers and indigenous groups, offering a practical and effective way of ensuring that SIA findings influence the development and operationof resource projects. While the case studies relate to specific regional, political, and cultural contexts, the general approach outlined in the article should be of interest to indigenous communities and SIA practitioners.