This article provides a systematic review of the potential and limitations of mobile phones in the delivery of rural services for agricultural and rural development in developing countries. The review indicates a rapid expansion of research in recent years, and a growing number of primary research studies that have developed rigorous methodologies for data collection and analysis, with welcome contribution from developing country institutions and researchers. Gaps in the literature suggest areas where future research priorities may lie. These include the provision of agricultural data sources that can provide the basis for effective planning and policymaking, and the assessment of information and service needs that take into account gender differences and the potential for user involvement in the design of service provision. Research is also needed to assess the potential for financial market integration, sustainable business models, consideration of indicators of sector performance and productivity, and assessment of broader impacts at the community and societal level.