This study aimed at the technical-economical evaluation of implanting some vegetal-oil extraction units in order to insert the family agriculture into bio-diesel production chain. Three project models (arrangements) for vegetal-oil extraction units at different sizes were proposed, using extraction by pressing and mixed extraction (extracting by either pressing or solvent) and different raw materials (castor-oil and soybean). For the size analysis, the oil production scales between 50/60 tons/day were used with real market data concerning investments, inputs prices of the process, raw materials and vegetal oil. For the economic analyses, the software BioSoft was used. The BioSoft is a program for supporting the decision-making process, which was developed through analyzing units of bio-diesel production, and it was adapted to evaluate units of vegetal oil extraction. It was concluded that the unit of chemical extraction producing castor and soybean oils shows more satisfactory results. However, this model presents less social return because the number of the families involved is lower, once, in using soybean, it operates with only 50% of raw material deriving from family agriculture.