The objective of this study was to evaluate the weight and body yield of two families of selectively bred tambaqui farmed in different environments. Two families (FA and FB) were reared in the municipalities (environments) of Santo Antônio de Leverger (MT) and Campo Grande (MS) for 431 days. Pre-bleeding weight, body yield, and the interaction effect between families and environments on these traits were investigated. No interaction effect between the evaluated families and environments was detected on the evaluated traits. Pre-bleeding weight did not differ significantly between the families in MT (FA: 2,421.7g; FB: 2,478.0g) or in MS (FA: 1,138.7g; FB: 1,389.8g), but the fish from MT had a higher (P<0.05) pre-bleeding weight than those farmed in MS. The visceral fat yield (considering the two environments) was higher (P<0.05) in FB family (3.8%) than in FA family (3.3%).Fish from MS showed higher (P<0.05) offal yield (10.6%) and visceral fat yield (3.9%) but a lower clean-trunk yield (70.6%) than the tambaqui farmed in MT (offal: 7.7%; visceral fat: 3.1%; and clean trunk: 72.6%). In conclusion, the MT environment provides higher pre-bleeding weight and clean-trunk yield and lower offal and visceral-fat yields than the MS environment.