Commodity markets have become key forces transforming upland livelihoods, social relations and landscapes in Vietnam and throughout Southeast Asia. This paper examines the processes of market formation and their effects on local livelihoods and social relations in a village of Vietnam's north-western uplands. The results indicate that villagers’ reactions to new opportunities arising from decollectivization and market liberalization wove them into an increasingly intricate ‘commodity web’. Differences among households widened as households with an initial advantage accumulated further advantages. Yet the relations governing access to land and product markets also provided a floor of subsistence for the disadvantaged. The findings demonstrate the need to interrogate commodity markets, investigate the practices and relations constituting them, and analyse how they distribute income and risks among the actors involved. The nature of commodity markets, together with the relations governing access to productive resources, influences processes of social differentiation in the uplands.