Achieving and sustaining universal access to contraceptives are key policy goals of interventions supplying contraceptive commodities. Donor support for contraceptive supplies is substantial and many public and national programmes rely on donated and subsidized supplies of contraceptives. Sustainability of programme benefits is a concern to both national governments and donor agencies. At the same time, market-based provision of contraceptives has become a major source of contraceptives for individuals in a number of countries. While the goals or 'ends' of policy are to increase and sustain universal access to contraceptives, there is debate about the role of markets and their negative impacts on equity and universality. There is also concern that while public programmes supplying free contraceptives may, in the medium-term, achieve high coverage, they may hamper the achievement of long-term sustainability and the development of commercial markets. This paper focuses on the tension between the public health and market paradigms, and uses economic analysis as a framework in order to examine the relative roles or 'means' for subsidized public and commercial private sector supply of contraceptives. The review of the theory and evidence focuses on the trade-offs between public sector and market provision of contraceptives, examining the role for the public sector given the potential for market failures, the impact of public provision on the development of markets, and the role of price in demand. However, because of the potential conflict between these policy objectives, we argue that strategies to deliver contraceptives should be based on the specific characteristics of the context. In particular four variables (contraceptive prevalence rates, HIV prevalence, income level of country, size and geographic spread of private sector development) are important in characterizing this context, and these are highlighted in a matrix of programme priorities. Public choices need to take into account the ways in which they will affect the potential for development of sustainable private sources of supply. Undertaking a 'market assessment' should be a key stage in the analysis of policy options. Such an assessment should address demand factors, health priorities, actual and potential sources of supply and the relationships between public and private supply. Clearly the development of markets for contraceptives is not an end in itself, but may prove an important means of improving the health of women and men.