Quinoa has been a staple food for Andean populations for millennia. Today, it is a much-appreciated product on the international health-food, organic and fair-trade food markets. Quinoa producers in the southern Altiplano of Bolivia initiated this change approximately 40 years ago. On high desert land, they succeeded in developing a thriving agricultural crop for export. Although they enjoy lucrative niche markets, quinoa producers are not specialized farmers, nor do most of them live yearround in the production area. These are some of the paradoxes that characterize quinoa production in the southern Altiplano of Bolivia. Following a description of the origin, diversity and biological traits of the 'Quinoa Real' ecotype, on which production in this area is based, this chapter explores the importance of quinoa in local agrosystems and in the systems of agricultural and non-agricultural activities managed by southern Altiplano families. Geographic mobility and pluriactivity are part of the ancestral lifestyle of these populations and have to date determined how territorial resources are used and producers are organized in the context of quinoa's commercial success. Quinoa production in the region is presenting signs of agro-ecological and social vulnerability; however, it has the capacities to respond and adapt accordingly. Key points for the sustainability of local agrosystems are: i) harmonization of communal and individual regulations concerning access to and use of land in socially equitable agrosystems with a balance between crops and animal husbandry, ii) international standards for the recognition of 'Quinoa Real' in export markets, iii) continuous updating of rules and regulations so that local agrosystems can adapt to unpredictable changes in the socio-ecological context on different scales of space and time.