Increasing food production and its sustainability is a crucial need due to population growth and environmental concerns. The application of agroecological principles enables to build innovative cropping systems, but their adoption remains limited. Agroecological transition involves complex, multi-dimensional challenges at various levels, from farming to agrifood systems. So far, sociotechnical analyses were conducted to understand historical lock-ins in agriculture, but without giving strong attention on the interactions between farmers and other actors. Based on both farming system research and sociotechnical system studies, and on 4 previously published case studies,the article proposes a new approach called “sociotechnical inquiry approach” (STIA) based on a 5-step methodology. The STIA explicitly considers how agrifood system actors influence farmers’ decisions, and aim at identifying barriers and levers for agroecological transitions at territorial and value-chain scales. A cross-cutting analysis of the 4 case studies show that such an approach is likely to initiate multi-actor innovation processes that transform not only farmers' practices, but also those of a diversity of actors in the agrifood system. Its outputs are thus useful for designing coupled innovations, combining technological, organizational and institutional changes that are usually carried out independently by different actors.