Farmers are plant breeders when they select and save the seeds of the plants best adapted to the conditions in their fields. For over two decades, farmer breeders in Honduras have been working with scientists and NGOs to develop new bean varieties. In a context of high agrobiodiversity, limited public sector agricultural research capacity and extension services, the process has not always been smooth. Against all odds, this collaborative effort, which has brought scientific knowledge together with farmer knowledge, has positioned farmers at the forefront of innovation for climate change adaptation. This article highlights lessons learned over 20 years about the power of knowledge co-creation.