Post-Harvest Loss (PHL) reduces the income of smallholder farmers (SHFs) by 15 percent and results in reduced food supply in developing regions. To address this problem, The Rockefeller Foundation launched the YieldWise Initiative in 2016, which focused on reducing PHL by focusing on fruits, vegetables, and staple crops in Kenya, Nigeria, and Tanzania—countries where up to half of all food grown is lost. Specifically, the initiative targets four identified value chains - Mango in Kenya, Tomato and Cassava in Nigeria and Maize in Tanzania. This PHL Toolkit brings together the lessons we have learned through the lii YieldWise Initiative. The toolkit will illuminate the evidence of impact, new knowledge and areas where the initiative was not successful. The toolkit will be a “how to do guide” that provides a blueprint for actors interested in investing in PHL reduction interventions that can be taken to scale for high impact.