This paper analyzes the impact of participation in multi-stakeholder platforms (Plataformas) aimed at linking smallholder potato farmers to the market in the mountain region of Ecuador. It describes and evaluates the Plataformas’ program to determine whether it has been successful in linking farmers to higher-value markets and the effects that such connections have brought, particularly with regard to farmers’ welfare and to the environment. The analysis is run comparing a set of different and carefully constructed control groups to beneficiaries and using various specifications. Results are strongly consistent across the different specifications and are sound across the counterfactuals, suggesting impacts are adequately identified. Findings suggest that the program was successful in improving the welfare of beneficiaries, while potential negative environmental impacts, particularly with relation to agrobiodiversity and use of agrochemicals seem not to be a concern. Mechanisms through which impacts have been achieved are analyzed. Little spillover effects are found.