Wildlife is used for a range of purposes such as food, healthcare and ornamentation. Most wildlife trade is legal, contributing to livelihood and income generation for many people including some of the world’s poorest. However, the part of wildlife harvesting and trade occurring outside the laws is considered the biggest threat to conservation after habitat loss and overexploitation. Although illegal wildlife trade has received attention from the conservation and biological perspectives, there have been few studies on the root causes and socio-economic context influencing this activity. This paper studied illegal wildlife trade in and around the Kailash Sacred Landscape (Nepal, Western Himalaya), an area bordering both India and China. The causes identified were high demand for wildlife items (mostly in China), limited other livelihood opportunities for local people, open or porous borders, weak patrolling due to limited resources, and ineffective law enforcement. Efforts to tackle illegal wildlife trade should focus on awareness raising programs, mobilization of local people to gather intelligence, increased patrolling, and transboundary cooperation. Major trade routes and junctions identified in this study could help deploy patrolling and conservation efforts where they count.