The last decade has seen an increasing advancement and interest in the integration of agroecology and participatory action research (PAR). This article aims to: (1) analyze the key characteristics and principles of two case studies that integrated PAR and agroecology in Central America; and (2) learn from the lessons offered by these case studies, as well as others from the literature, on how to better integrate PAR and agroecology. Key principles identified for effective PAR agroecological processes include a shared interest in research by partners, a belief in collective power/action, a commitment to participation, practicing humility and establishing trust and accountability. Important lessons to consider for future work include: (1) research processes that did not start as PAR, can evolve into it; (2) farmer/stakeholder participation in setting the research agenda, from the outset, results in higher engagement and enhanced outcomes; (3) having the right partners for the desired outcomes is key; (4) intentional and explicit reflection is an essential component of PAR processes; and (5) cross-generational collaborations are crucial to long-term benefits. Key challenges that confront PAR processes include the need for time and resources over longer periods; the complexity of multi-actor process facilitation; and institutional barriers within the academy and development organizations, which prevent shifting investment towards integrated PAR agroecological processes.