This article presents research findings into the effectiveness of an innovative equity fund approach to improving access to public sector health services for the poor in Kirivong Operational Health District in Cambodia. The operational health district is the lowest organizational level in the Cambodian health system, providing services through health centres and a single referral hospital. An equity fund involves a third party identifying the poor and paying user fees on their behalf by reimbursing the service provider, thus relieving health staff of such responsibility. We explore the appropriateness of utilizing community members to identify the poorest. The impact of newly introduced pagoda-managed equity funds on access to public health services for the poorest, and on their out-of-pocket expenditure during illness episodes, is then examined. We conclude with an evaluation of the contribution of the equity funds to community participation. The research indicates that identification by community members of those eligible for equity funds is feasible, accrues minimal direct costs, and is effective. Households identified as eligible for equity fund benefits were poorer than those identified as non-beneficiaries. Direct costs associated with seeking care were considerably lower for equity fund beneficiaries than for non-beneficiaries, and fewer beneficiaries than non-beneficiaries initially consulted the private sector, providing evidence of the equity fund's ability to attract the poorest to the public sector. The level and nature of community participation was enhanced considerably following the introduction of the pagoda-managed equity funds. In order to maximize and sustain the equity benefits of such funds, we recommend that external agencies (such as international non-governmental organizations) limit their role to the provision of technical support and advice, rather than taking the lead on implementation and administration. Facilitating the design, implementation, administration and management of equity funds by indigenous community-based organizations has the advantage of not only greatly reducing administrative costs, allowing a large proportion of the fund to be spent on services for the poor, but also of enhancing local ownership, thus increasing the likelihood of equity funds being sustained in the future.