Finding and implementing innovative solutions to sustainability problems in agriculture makes collaboration among farmers and other stakeholders indispensable. There has already been much work on conditions influencing success or failure of joint action in different contexts. However, aside from not providing insights specifically for collaboration in the context of sustainable agriculture, much of this research has been based on the investigation of one or few case studies. Other works have investigated more specifically collaboration in the context of sustainable agriculture. Yet, there is a lack of research on collaboration for sustainable agriculture that integrates insights in both internal and external factors for success and that assesses these factors against explicit and comprehensive success criteria. To fill these gaps, this research provides first results of a case survey of case studies of local or regional collaborative interventions in EU-countries that attempt to improve the sustainability of agriculture. The aim of this case survey is to identify which conditions contribute or hamper general success of such interventions. Specifically, the first eight coded case studies were analysed to explore existence and type of causal relations between the (long-lasting) success of an intervention and factors related to group composition and social capital among involved actors on the one hand and factors of organisation and management of these interventions on the other hand. Apart from indicating a range of factors that potentially have an effect on the success of collaborative interventions for a more sustainable agriculture, for a selection of these factors mechanisms were identified through which this influence on success may occur.