This  dissertation  aimed  to  analyze  the  process  of  rationality  that  sustains  the  decision  of family farmers to produce or stop producing tobacco. To that end, 63 farmers from Vale do Rio Pardo microregion, in the state of Rio Grande do Sul, were interviewed. The information was analyzed with the analytical aid of bounded rationality, proposed by Herbert Simon and used by scholars of the New Institutional Economics. Using this approach, it was sought to understand  the motivations  and  factors  that  lead  the  farmers  to  grow  tobacco.  The  analysis was  developed through  quantitative  and  qualitative  data  empirically  obtained  in  a  semi structured questionary used to conduct the interviews with farmers. Through the identification of key players involved in tobacco production, it was found that the activity is the result of a complex organizational and social structure consisting of many interdependent agents. Their performances are based on social, cultural and economic rules established by the institutional context. The relationships between farmers and agribusinesses are characterized by a pattern of  uneven  and contradictory  development.  Despite  the  bounded  rationality,  the  reactions  of farmers across the cognitive conflict caused by dissatisfaction with their current situation and few or no alternatives for change  are essentially linked to structural and subjective elements.

Even  considering  the  action  of  bounded  rationality,  structural  and  subjective  elements,  the current situation of farmers and their future projects, in many cases found in this study, their reactions  to  the  decision  to  produce  or  stop  producing  tobacco  are  more  guided  by  lack  of choice  than  by  the  action  of  bounded  rationality  of  farmers.  Added  to  these  factors  are farmers´ deficiencies in organization and incomplete information on the productive sector.