Stand-alone electrification systems based on the use of renewable energies are suitable to electrify isolated rural communities in developing countries. For their design several support tools exist, but they do not cover some of the technical and social existing constraints and they do not consider the project detail. In this context, this research aims to develop a methodology to optimize the design of such systems, combining the wind and solar generation technologies as well as microgrids and individual systems as distribution scheme, and including economical, technical and social considerations. The design methodology is divided in three stages. First, the characteristics of the target community are gathered. Secondly, the design process is realized in three decision levels, ordered according to the importance of the decisions taken. At each level several electrification alternatives are generated and then the most appropriate is selected. Third, the final solution cost can be optionally tried to be improved, maintaining the decisions previously taken. The design methodology has been applied to a community to show its suitability to assist rural electrification promoters to design socially adapted and sustainable projects.