Given the need to define sustainability in agricultural cropping systems, we sought to understand and apply a simple methodology for analysing sustainability in different agricultural systems on a rural property in the north-east of Pará. The agro-ecosystems studied were an Agroforestry System, a Conventional Cassava Cultivation System, a Pasture System and the Forest Ecosystem, with the aim of analysing their sustainability, comparing and relating the levels of sustainability using predetermined indicators in tables and questioning the farmer.