Community participation in health (CPH) has been advocated as a health-improving strategy for many decades. However, CPH comes in many different forms, one of which is the use of health facility committees (HFCs) on which there is community representation. This paper presents the findings of a systematic literature review of: (a) the evidence of HFCs' effectiveness, and (b) the factors that influence the performance and effectiveness of HFCs. Four electronic databases and the websites of eight key organizations were searched. Out of 341 potentially relevant publications, only four provided reasonable evidence of the effectiveness of HFCs. A further 37 papers were selected and used to draw out data on the factors that influence the functioning of HFCs. A conceptual model was developed to describe the key factors. It consists of, firstly, the features of the HFC, community and facility, and their interactions; secondly, process factors relating to the way HFCs are established and supported; and finally, a set of contextual factors. The review found some evidence that HFCs can be effective in terms of improving the quality and coverage of health care, as well as impacting on health outcomes. However, the external validity of these studies is inevitably limited. Given the different potential roles/functions of HFCs and the complex and multiple set of factors influencing their functioning, there is no 'one size fits all' approach to CPH via HFCs, nor to the evaluation of HFCs. However, there are plenty of experiences and lessons in the literature which decision makers and managers can use to optimize HFCs.