Social impact assessment (SIA) is now conceived as being the process of managing the social issues of development. There is consensus on what ‘good’ SIA practice is – it is participatory; it supports affected peoples, proponents and regulatory agencies; it increases understanding of change and capacities to respond to change; it seeks to avoid and mitigate negative impacts and to enhance positive benefits across the life cycle of developments; and it emphasizes enhancing the lives of vulnerable and disadvantaged people. We analyse the strengths, weaknesses, opportunities and threats facing SIA. We assert that the SIA community needs to revisit core concepts, such as culture, community, power, human rights, gender, justice, place, resilience and sustainable livelihoods. It is incumbent on SIA practitioners to educate proponents, regulators and colleagues about these concepts, and to embed them into practice norms. Stronger engagement with the emerging trends of free, prior and informed consent (FPIC); human rights impact assessment; social performance standards; supply chain management; governance; local content and economic development will improve the relevance and demonstrable value of SIA to all stakeholders.