Evidence is emerging from rigorous evaluations about the effectiveness of nutrition-sensitive agriculture programmes in improving nutritional outcomes. Additional evidence can elucidate how different programme components and pathways contribute and can be optimized for impact. The International Food Policy Research Institute, with Helen Keller International, designed a comprehensive framework to evaluate the delivery, utilization, and impact of Helen Keller International's enhanced homestead food production programme in Burkina Faso. After 18 months of implementation, a process evaluation was conducted to examine programme impact pathways, using key informant and semistructured interviews with implementing agents and beneficiaries, and with residents of control communities. Data were analyzed by International Food Policy Research Institute and reviewed with project managers and partners through multiple workshops to identify opportunities to strengthen implementation. Findings illuminated gaps between intended and actual delivery schemes, including input constraints, knowledge gaps among community agents in agriculture and young child nutrition practices, and lower than expected activity by community volunteers. In response, staff developed measures to overcome water constraints and expand vegetable and poultry production, retrained volunteers in certain techniques of food production and counselling for nutrition behaviour change, added small incentives to motivate volunteers, and shaped both immediate and long-term changes to the programme model. Working closely with International Food Policy Research Institute on the evaluation activities also expanded the repertoire of research methods and skills of Helen Keller International staff. Process evaluation can strengthen programme delivery, utilization, and design. Collaboration between researchers and implementers can improve programme effectiveness, project staff capacity, and advance delivery science.