The work analyzes the political/institutional links and technological formats of agroforestry systems in the Caí and Taquari river valleys of the Brazilian state of Rio Grande do Sul in an effort to determine a value for their ability to endure: their sustainability. Sustainability indicators are created for the analysis of these systems. The indicator values will be used to create a Sustainability Index (SI) for each studied agroforestry system and to identify each system’s sustainability pattern. The different agroforestry systems will also be classified according to their structural characteristics. Analysis of the identified patterns and indexes will reveal the adequacy of the methodology employed and the consequence of each system’s institutional arrangement, technological format, and sustainability pattern. The agro forestry system that combines exotic forest species with watermelon and the system that combines native forest species with citrus fruit stand out as being most sustainable while, from an institutional perspective, those systems that were linked in an "associative" arrangement had the highest sustainability index values.