Information sharing is considered an important approach to increasing organizational efficiency and performance. With advances in information and communication technology, sharing information across organizations has become more feasible. In the public sector, government agencies are also aware of the importance of information sharing for addressing policy issues such as anti-terrorism and public health. However, information sharing can be a complex task. Identifying factors that influence information sharing is critical. In the literature, research in information sharing focuses on the interpersonal, intra-organizational, and inter-organizational levels. This paper reviews the current information-sharing research, discusses the factors affecting information sharing at the three levels, and provides summative frameworks. These frameworks provide a means to discover future research opportunities, and a systematic way for practitioners to identify key factors involved in successful information sharing. ► Interpersonal information sharing. ► Intra-organizational information sharing. ► Inter-organizational information sharing. ► The interrelationship of the three contexts.