The aim of this paper is to map and critically analyse evidence of good practice in prevention and response to gender-based violence (GBV) in humanitarian contexts which can support humanitarian practitioners and policy makers to improve the quality of GBV programming in the field. The paper is structured as follows. Following a brief discussion of key concepts and definitions in relation to GBV, Chapter 2 presents an overview of the extent of GBV in emergencies, and some of the challenges in responding to the problem. Chapter 3 then analyses some of the literature on the evidence of GBV programming effects in humanitarian settings, and draws out key lessons with regard to good practice. Chapter 4 discusses some of the key issues emerging from this review, and Chapter 5 concludes the paper with a discussion of the implications of the findings for research, policy and programming on GBV.