Brazilian South and Southeast regions produced more than 50% of the Brazilian agricultural production in 2006. The Brazilian government has implemented several policies to enhance farm income on these regions such as policies towards enhancement of cooperatives production management. This directly affects farmers in these regions given that around 24% of them were members of cooperatives. In this paper, we estimate the effect of this membership on farms profitability, output supplies and input demands. To calculate these effects, we estimate a quadratic normalized restricted profit function using the Brazilian Agricultural Census of 2006 for the South and Southeast regions of Brazil. Preliminary results suggest a positive effect of cooperative membership on profit of about US$ 4.1 million per year. A positive effect of membership on output supplies and on input demand was found. Acknowledgement : The authors acknowledge the suggestions of the reviewers. Some of them will still be implemented. Foundation for the Coordination and Improvement of Higher Level or Education Personnel (Capes - Brazil) Applied Economics Program, Dept. of Agricultural Economics Federal University of Vi osa-MG.