Agricultural Extension services are among the most important rural services in developing countries. The services are considered to be a key driver of technological change and productivity growth in agriculture. In Kenya, like in the rest of the developing economies, agricultural extension has largely been delivered through supply–driven approaches. Due to perceived low impact of agricultural extension, the country is implementing the National Extension Policy (NEP) which advocates for demand–driven extension and participation of other players. Using the case of the smallholder tea sub-sector, this paper examines the effects the FFS extension on tea crop yields in Kenya. The FFS system uses participatory approaches including the demonstration of best sustainable practices in the farms and farmers learn by doing. Data for the study was collected from a sample of 525 farm households in Western Kenya using a multi stage random sampling procedure and analyzed using the propensity score matching (PSM) model which controls for self-selection endogeneity. The results show that participation in FFS extension increases annual tea yields by an average of 471.70 kgs per acre (p = 0.009) while the farmer–funded train and visit system has no influence on crop yields. A part from showing the contribution of FFS to crop yields, the paper demonstrates that the supply–driven extension models including T&V are necessary to stimulate demand in the initial stages of implementing the FFS models. Based on the findings, investments to enhance FFS access among smallholder farmers are recommended. تفاصيل المقالة