Highlights: • We combined SWOT analysis and co-design workshops to study diversification options. • The approach was applied in five case studies in the Mediterranean basin. • Intercropping was seen as the most promising solution in most case studies. • New cereal-based rotations included legume species, or rapeseed. • New systems provided a partial solution to local environmental and economic threats. Abstract: Agriculture today faces opposing challenges: reducing its environmental impacts while feeding a growing population and adapting to climate change. Diversification of cropping systems has been proposed as a solution to address these issues and promote sustainable and resilient agricultural systems. While alternatives have been proposed by research and development, changing the agricultural systems remains a huge challenge. Engaging local actors when considering those changes is important for their successful implementation. While co-designing with stakeholders is gaining interest in the scientific community, approaches that consider varying local contexts remain uncommon. In this study, our aim was to co-design, during workshops with local stakeholders, diversification options in five case studies located in the Mediterranean countries of Algeria, France, Greece, and Spain. Prior to the co-design process, we conducted a SWOT/PESTLE analysis in each case study to analyze the local context of current and potential agricultural systems. Our hypothesis was that co-designed systems would differ between case studies, according to their environmental, social and political contexts leading to fine-tuned locally ad hoc systems. Options for intercropping and diversifying rotations were considered for both cerealbased systems and vine systems. Additionally, these options included adapted management practices for cereal-based systems and more innovative diversification, such as photovoltaic panels or agroforestry, for vine systems. While some of these options could serve as adaptations to climate change, they may not be sufficient to address future climate conditions. Interestingly, we did not observe significant differences among the system options designed for the various case studies, even though the local contexts were very different. Indeed, options only partially addressed the issues identified by stakeholders: primarily, economic and environmental threats. This study points to the advantage of participatory research in diverse contexts along with cross-case analyses, and to the need to consider the future of these Mediterranean regions, where crop diversification is limited by water deficit. To foster the transition next steps should consider assessing experimentally these systems with farmers to stimulate learning, while considering market possibilities.