Agriculture Market Information Systems (MIS) are designed to collect, process and disseminate information on agricultural markets in order i) to improve public policies through increased awareness of market realities and ii) to increase market transparency and, by this way, to lead to a fairer and more efficient allocation of resources. Small farmers' market power is often hindered by their lack of information on price level at different points of the marketing chain; MIS aims to strengthen their bargaining position by a better access to information. In addition, market information can be used by farmers to guide their production and marketing decisions, and by farmers' organizations for advocating for more producer-friendly policies. However, although a large number of MIS has been developed, their effectiveness in reaching farmers is often far from expectations. This brief first presents the different options of MIS development in Burkina Faso, Tanzania and Zambia. Then, lesson learned from these FARMAF experiences, as well as additional cases in Sub-Saharan African, are discussed.