This paper analyzes integrated natural resource management (INRM) lessons and success factors based on a practical case study over more than 10 years in Zimbabwe. The work was geared toward enhancing the adaptive management capacity of the stakeholders in their resource-use systems. One main result was the development and institutionalization of an approach for participatory and integrated NRM research and extension. The INRM approach described is grounded in a learning paradigm and a combination of theories: the constructivist perspective to development, systemic intervention, and learning process approaches. Participatory action research and experiential learning, in which researchers engage themselves as actors rather than neutral analysts in an R&D process to explore the livelihood system and develop appropriate solutions together with the resource users, has shown high potential. However, this should be guided by a clear strategy, impact orientation, and high-quality process facilitation at different levels. The case study revealed the importance of a “reflective practitioner” approach by all actors. More effective response to the challenges of increasing complexity in NRM requires a shift in thinking from the linearity of research–extension–farmer to alternative, multiple-actor institutional arrangements and innovation systems. To overcome the weak attribution of research outcomes to actual impact, it also suggests an alternative to conventional impact assessment in INRM R&D interventions.