Kinaka or Chikanda has been eaten by people in parts of Zambia, northern Malawi and south-western Tanzania for hundreds of years. Prepared from the boiled root tubers of terrestrial orchids, and principally from species of the genera Disa, Habenaria and Satyrium, it was formerly a traditional village delicacy and did not pose a threat to orchid populations. However, the past decade has witnessed a dramatic rise in demand in Zambia, particularly in urban areas. This has triggered a burgeoning commercial market and has now prompted traders to seek tubers from Tanzania's Southern Highlands, an important centre of endemism for upland species of orchid. The resulting cross-border trade, its dynamics and the implications for Tanzanian orchids are reported here for the first time. Whilst all orchid species are in CITES Appendix II, collectors are currently harvesting between 2.2 and 4.1 million tubers per year for export to, and consumption in, neighbouring Zambia. As many as 85 species may be at risk from this trade, and there is evidence that large areas in Ufipa, Mbeya and Kipengere have already been stripped of their orchids. A decline in traditional Tanzanian consumption of Kinaka seems to be having little or no impact on harvesting volumes. Orchid collection across the Southern Highlands is now escalating at a rate that may be far from sustainable. The consequences for Tanzanian biodiversity and for one of Africa's most important areas for orchids are profound.