In French peri-urban regions, more and more large-scale field crop farmers, historically long chain-oriented, are willing to diversify production with vegetables sold through local and/or short marketing channels. This horticultural diversification seems mainly drawn by the commercial opportunity of increasing urban demand for local vegetables but could potentially bring other benefits: better added value and image (in peri-urban areas where neighboring inhabitants can have a negative perception of industrial farming), job creation or extending crop rotation as an agroecological strategy to reduce inputs. However, this horticultural diversification is very little documented and farmers can face many doubts and challenges that may limit the transformation of peri-urban production systems. Our research objective is to analyze (i) the different modalities of horticultural diversification at the farm level: which vegetables are integrated? on which acreage? how are vegetables integrated in the production system (as part of field crop rotations or on dedicated acreages?) for which objectives? and (ii) the consequences, impeding or favoring factors of horticultural diversification for peri-urban field crop farmers (workload organization, skills, equipment and investment, farming practices, marketing strategies, profitability etc.).