In this article we outline research since 1995 on the impact of various financing strategies on access to health services or health outcomes in low income countries. The limited evidence available suggests, in general, that user fees deterred utilisation. Prepayment or insurance schemes offered potential for improving access, but are very limited in scope. Conditional cash payments showed promise for improving uptake of interventions, but could also create a perverse incentive. The largely African origin of the reports of user fees, and the evidence from Latin America on conditional cash transfers, demonstrate the importance of the context in which studies are done. There is a need for improved quality of research in this area. Larger scale, upfront funding for evaluation of health financing initiatives is necessary to ensure an evidence base that corresponds to the importance of this issue for achieving development goals.