Positive deviance is a growing approach in international development that identifies those within a population who are outperforming their peers in some way, eg, children in low-income families who are well nourished when those around them are not. Analysing and then disseminating the behaviours and other factors underpinning positive deviance are demonstrably effective in delivering development results. However, positive deviance faces a number of challenges that are restricting its diffusion.In this paper, using a systematic literature review, we analyse the current state of positive deviance and the potential for big data to address the challenges facing positive deviance. From this, we evaluate the promise of "big data-based positive deviance": This would analyse typical sources of big data in developing countries-mobile phone records, social media, remote sensing data, etc-to identify both positive deviants and the factors underpinning their superior performance. While big data cannot solve all the challenges facing positive deviance as a development tool, they could reduce time, cost, and effort; identify positive deviants in new or better ways; and enable positive deviance to break out of its current preoccupation with public health into domains such as agriculture, education, and urban planning. In turn, positive deviance could provide a new and systematic basis for extracting real-world development impacts from big data. KEYWORDS big data, developing countries, machine learning, mobile data, positive deviance, systematic literature review 1 | INTRODUCTIONMany development practitioners continue to use a traditional "needs-based" approach to development, involving top-down identification of needs and problems, and the external imposition of solutions that meet those needs. This type of approach can work well in addressing specific technical challenges. But it works much less well where development requires learning and behavioural change by beneficiary groups, something which necessitates much greater knowledge of and engagement with beneficiary communities (Nel, 2018;Pascale, Sternin, & Sternin, 2010;Saïd Business School, 2010;Singhal, 2011). As a result, more bottom-up "asset-based" approaches have come into existence, which capitalize on a community's inherent assets and capabilities-including knowledge-in solving development problems. Positive deviance (PD) is one such assetbased approach. It is based on the observation that in every group or community, a few individuals use uncommon practices and behaviours to achieve better solutions to problems than their peers who face the same challenges and barriers (Pascale et al., 2010). Those individuals are referred to as "positive deviants" (PDs), and adopting their solutions on a wider basis is referred to as the PD approach.The term "positive deviance" was first used in 1976 to describe a practical strategy for the design of food supplementation programmes in Central America, a strategy that was derived endogenously rather than exogenously through identify...