Biofuel production has been a greatly discussed topic in Brazil. In 2004, these debates led the country to develop new policies and implement a national program for biodiesel use and production (PNPB) with the intent to foster a sustainable rural development. In this context, the present study aims to assess the impacts of the PNPB on rural development in the Brazilian Legal Amazon, in a region of transition between Savannah and Amazon Rainforest. Ranges of socio-economic indicators were collected among smallholders who cultivate Jatropha curcas and Ricinus communis and a linear programming model (LP) was applied at the farm level to simulate strategies and scenarios for the adoption of oil seed activity by farmers and, therefore, the impacts on farm and family income. For this purpose, the software GAMS (General Algebraic Modeling System) was used to support the modeling simulations.