In the world’s highest tropical mountain range, the Cordillera Blanca of Peru, impacts linked to climatic change, increasing pressures on water resources, rapidly rising petroleum costs and shifting market conditions are threatening the viability of agricultural systems. Currently, these distinct processes of change are converging in ways that significantly enhance and reinforce their negative effects on the livelihood security of rural populations in this region. Based on new case study research comprised of extensive surveys and interviews with a broad range of regional stakeholders, the authors illustrate the ways in which highland farmers and their agricultural pursuits in the Cordillera Blanca are increasingly vulnerable to these intersecting changes.