This review aims to identify, assess and analyse the evidence on equity in the distribution of public health sector expenditure in low- and middle-income countries. Four bibliographic databases and five websites were searched to identify quantitative studies examining equity in the distribution of public health funding in individual countries or groups of countries. Two different types of studies were identified: benefit incidence analysis (BIA) and resource allocation comparison (RAC) studies. Quality appraisal and data synthesis were tailored to each study type to reflect differences in the methods used and in the information provided. We identified 39 studies focusing on African, Asian and Latin American countries. Of these, 31 were BIA studies that described the distribution, typically across socio-economic status, of individual monetary benefit derived from service utilization. The remaining eight were RAC studies that compared the actual expenditure across geographic areas to an ideal need-based distribution. Overall, the quality of the evidence from both types of study was relatively weak. Looking across studies, the evidence confirms that resource allocation formulae can enhance equity in resource allocation across geographic areas and that the poor benefits proportionally more from primary health care than from hospital expenditure. The lack of information on the distribution of benefit from utilization in RAC studies and on the countries' approaches to resource allocation in BIA studies prevents further policy analysis. Additional research that relates the type of resource allocation mechanism to service provision and to the benefit distribution is required for a better understanding of equity-enhancing resource allocation policies.