One of the main goals of a country is to achieve a degree of food selfsufficiency. South America produces all the food products that are required to satisfy the caloric requirements as well as to have a balance diet; this is possible as it counts with all kind of crops, from tropical to temperate and cold weather. However, there exists a systematic loss of food self-sufficiency (more imports in relation to domestic consumption) among UNASUR countries in the last 50 years. This loss of food self-sufficiency has implications also in the quality of the diet. The higher dependence observed obeys to structural factors associated with the insertion in international markets (specialization as exporters of commodities) and with the lack of public policies in each country. The paper analyzes agricultural complementarity among UNASUR countries and the likely trade diversion that would come with it, as many imports from outside the region could be done internally, since there is availability. This goal requires coordination in regional macroeconomic and agricultural policies, deepening the levels of economic integration. Food self-sufficiency is important because it lowers transportation costs (and therefore CO2 emissions) and saves currency, which could be used for importing advanced technology, among other benefits.