Coffee grown under shade is the most commonly used coffee cultivation system in the tropics. It represents more than 7 millions ha of planted areas and 60% to 80% of the total world production. The practice involves more than 20 millions people, most of them being small farmers. In view of the current global coffee crisis and the increasing focus on poverty alleviation across the tropics, the Centre International pour la Recherche en Agronomie pour le Développement (CIRAD) and the World Agroforestry Centre (ICRAF) have launched a partnership initiative on coffee agroforestry systems. The initiative is expected to benefit small holders coffee farmers by enhancing improved income opportunities in a more sustainable production system. As a core element of the research framework, coffee based agroforestry is seen as a multidimensional system with biologic, economic and social components. The research agenda will therefore test the following assumptions: - that shade favors the quality of both Arabica and Robusta coffee. An appropriate, well organized local production chain could then help the farmer to match the International Coffee Organization (ICO) standards and to address the growing market of coffee specialty; - that trade-offs of the shade coffee system are globally beneficial for biodiversity, watershed, and soil preservation, as well as amelioration of pest and diseases; - that coffee agroforestry systems offer multiple, viable, options of diversified sources of income through associated crops and shade tree species with various uses (e.g. medicinal, fruit, timber); - that such systems would then offer more opportunities for sustainability in terms of economic viability and landscape management. For the farmers to achieve those goals, "good agroforestry practices" will be defined, to develop modem skills in tree management, adapted to the various areas in Africa, Asia and America where the ICRAF-CIRAD initiative should apply. (Texte intégral)