While consumers’ preferences and willingness to pay for local food have been widely explored, farmers’ choice of marketing channels in high-income countries has received far less attention. This study identifies important factors affecting fresh vegetable farmers’ decisions to participate in local short food supply chains in Wallonia, Belgium. We use quantitative data from a farmer survey comprising a discrete choice experiment complemented by qualitative data to conduct our research. We show that farmers are not eager to participate in newly established short food supply chains, especially if it involves selling large shares of their yield through these channels. Farmers are interested in internal certification systems with label, such as Participatory Guarantee Systems, and direct-to-consumer selling on-farm. Commitment from the buyer before planting is highly valued, even more than a high selling price. Preference heterogeneity is linked to farm size and current organic certification status. Our findings allow to evaluate the relevance and improve the design of local food initiatives, including newly established short food supply chains and certification systems.