The present work consisted of the supplementation of macaroni with fish protein concentrate (FPC) at the levels of 5, 10, 15, and 20% in relation to wheat flour. The FPC was obtained from eviscerated and deboned trairas (Hoplias malabaricus), using boiling ethanol as a solvent at a pH range of 5.5 to 6.0. The FPC showed desirable aspects such as bright color, no off-flavor, high levels of protein (84.3 g/100 g) and lysine (484 mg/g N) and low levels of fat (0.4 mg/100 g) and moisture (8.6 g/100 g). The macaroni became slightly dark in color with increasing additions of FPC. Nevertheless, the 20% level was the only one not accepted by the testing panel, in terms of color and flavor. Weanling Wistar rats were used in the biological assay to measure the macaroni protein quality at the different supplementation levels. Analyses of PER, NPR, NPU, digestibility and retained carcass N were carried out. The protein quality of the macaroni was improved by the addition of FPC. The level of 10% was similar to the casein and no subsequent improvement in the protein quality was notified with higher levels of FPC. Due to its high lysine content, the FPC is a promising supplement for cereals. From the nutritional and sensory aspects, the 10% level of FPC was the most satisfactory for macaroni supplementation.