Performance-based incentives (PBIs) aim to counteract weak providers' performance in health systems of many developing countries by providing rewards that are directly linked to better health outcomes for mothers and their newborns. Translating funding into better health requires many actions by a large number of people. The actions span from community to the national level. While different forms of PBIs are being implemented in a number of countries to improve health outcomes, there has not been a systematic review of the evidence of their impact on the health of mothers and newborns. This paper analyzes and synthesizes the available evidence from published studies on the impact of supply-side PBIs on the quantity and quality of health services for mothers and newborns. This paper reviews evidence from published and grey literature that spans PBI for public-sector facilities, PBI in social insurance reforms, and PBI in NGO contracting. Some initiatives focus on safe deliveries, and others reward a broader package of results that include deliveries. The Evidence Review Team that focused on supply-side incentives for the US Government Evidence Summit on Enhancing Provision and Use of Maternal Health Services through Financial Incentives, reviewed published research reports and papers and added studies from additional grey literature that were deemed relevant. After collecting and reviewing 17 documents, nine studies were included in this review, three of which used before-after designs; four included comparison or control groups; one applied econometric methods to a five-year time series; and one reported results from a large-scale impact evaluation with randomly-assigned intervention and control facilities. The available evidence suggests that incentives that reward providers for institutional deliveries result in an increase in the number of institutional deliveries. There is some evidence that the content of antenatal care can improve with PBI. We found no direct evidence on the impact of PBI on neonatal health services or on mortality of mothers and newborns, although intention of the study was not to document impact on mortality. A number of studies describe approaches to rewarding quality as well as increases in the quantities of services provided, although how quality is defined and monitored is not always clear. Because incentives exist in all health systems, considering how to align the incentives of the many health workers and their supervisors so that they focus efforts on achieving health goals for mothers and newborns is critical if the health system is to perform more effectively and efficiently. A wide range of PBI models is being developed and tested, and there is still much to learn about what works best. Future studies should include a larger focus on rewarding quality and measuring its impact. Finally, more qualitative research to better understand PBI implementation and how various incentive models function in different settings is needed to help pracctitioners refine and improve their programmes.practitioners refine and improve their programmes.