The aim of the study was to evaluate the effect of add of toasted bean Mucuna pruriens L. flour (TBMF) in isoenergetic and isoproteic diets, over the productive and economic indicators of Colossoma macropomum Cuvier 1818 (Gamitana) juvenile. During 183 days Gamitana juvenile were fed with palletized isoenergetic (ED 2700 kcal / kg) and isoproteic (PB 25%) diets, with four increasing levels of HTM (10, 20, 30 and 40%) and a control diet (without TBMF). 1000 Gamitana juvenile with an initial average weight of 12.7 g, distributed in five compartments of 360 m2, with a density of 0.56 fish /m2 were used, fed in two daily frequencies (7:00 and 16:00 hours), with an initial feeding rate of 8% and a final feeding rate of 1% of biomass. Every 14 days, 70 fish (35%) were sampled for each treatment to evaluate the growth in length and weight, in each sampling the amount of food to be supplied was calculated in the following 14 days. The water quality was monitored every 15 days, determining, temperature (°C), dissolved oxygen (mg/L) and transparency (cm). The results show that the productive indicators showed difference between the treatments evaluated (p<0.05), as well as, a linear effect determined by orthogonal polynomials (p<0.05). The treatment including 10% of TBMF in the rations showed the best productive and economic indicators, obtaining a final live weight of 486 g, daily weight gain of 2.47 g / day, total length of 28.5 cm, feed conversion ratio (TCA) of 1.71, partial net income of S /. 2.57 / fish, as a percentage of the net partial income of 67.9% and 100% survival. In conclusion, the TBMF can be used as an alternative ingredient to a maximum limit of 10% in the balanced rations for Gamitana juvenile.