This guide provides with important contributions to the literature on health micro-insurance schemes. Its main objective is to encourage promoters and operators and support their efforts to conduct a systematic feasibility study prior to the establishment or further development of a scheme.The term "health micro-insurance" encompasses a wide variety of schemes. These include: mutual health organizations, which are autonomous associations based on the solidarity and democratic participation of their members; insurance schemes, which are organized and managed by health care providers; health insurance schemes set up by other actors, such as NGOs, microfinance institutions, cooperatives or trade unions.Actually, in spite of their dynamic nature, health micro-insurance schemes, in general, are quite fragile. They do not possess the hindsight and experience needed for an accurate determination of the financial risks they face. The financial safeguards of such schemes – reserves, reinsurance – and their promoters' level of competence in the area of insurance are presently still limited.Given such a context, the foundations of these schemes –that is, the assumptions upon which they are based – must be particularly firm. A scheme will have greater chances of surviving, and subsequently of developing, if it is well designed from the outset. Therefore, conducting a feasibility study appears to be essential.The impetus for producing this guide grew out of two observations: in order to ensure the sustainability and viability of a health micro-insurance scheme, it is important to define its characteristics in terms of its particular context. The feasibility study is a key contributing factor - though not the only one - to the success of a scheme; the promoters involved must have a coherent set of methods and tools at their disposal in order to carry out this type of study.