Many countries have implemented laws and planning instruments to preserve farmland on the urban fringe. This paper aims at a better understanding of the governance changes in peri-urban farmland protection following decentralisation processes in France and Italy. We compare the implementation of farmland protection instruments in the two city regions of Montpellier and Rome. From a governance perspective, we highlight the practical issues of effectiveness and social acceptability arising from power devolution, different forms of governance, and the potential conflicts when planning control shifts to lower-than-regional bodies. Our analysis is based on qualitative methods. Primary data were collected through document analysis, participant observation and in-depth interviews aimed at understanding local stakeholders’ practices and points of view on access to farmland, housing and building rights. We find that around Rome and Montpellier, decentralisation has produced multiple decision-making authorities and increased the complexity of procedures. Despite more regulatory constraints in agricultural areas, farmland conversion has persisted. However, decentralisation processes have also changed ways of governing and favoured local alternative initiatives for farmland protection and farming development on the urban fringe. New modes of governance involve public local authorities, farmers’ representative bodies (Montpellier) and civil society organisations (Rome). In both cities, they have a positive but limited impact on the effectiveness of farmland protection instruments. Their social acceptability varies, depending on who is really included in the participation process.