The leaves of these Gnetum spp. lianas have long been harvested from humid forests for consumption and traded as a popular vegetable across the Congo Basin. Recent data on the current environmental, social and economic aspects of this forest product are however sparse. Value chain analysis was used to gather information on stakeholders involved in the chain from forest to consumer (small scale harvesters, traders, transporters, exporters and consumers), and on the socioeconomic values, volumes, sustainability and governance in major production areas and markets in Cameroon and Nigeria. At least 2,550 people work across the chain, which has seven main routes from forest to consumers. Gnetum contributes on average to 62% of a harvester’s annual income (1,125 US$). Dependence upon Gnetum-based incomes increases for those further from the forest, providing an average of 75% of retailer’s (1,268 US$) and 58% of exporter’s annual incomes (7,000 US$). The better organised Nigerian wholesalers earn almost double their Cameroonian counterparts. Simple processing neither adds much value nor greatly reduces perishability. Whilst a rudimentary regulatory framework exists, trade is mostly illegal. Sporadic customary governance does not fill the void left by unenforced and inappropriate regulation. Over 50% is unsustainably collected from the forest and harvesting over the last 5 years increased as demand rose, particularly from Nigeria. Decreasing availability, increasing prices and low levels of cultivation have led to an unsustainable trade. Policy measures such as linking chain stakeholders, promoting cultivation, pragmatic regulation and enforcing customary control may enhance long-term survival of these IUCN Red List near-threatened species and ensure the continuity of their contribution to livelihood and economic development to continue.