SUMMARY The objective of this study was to evaluate the performance, carcass, meat quality, fatty acid profile and liver alterations of cattle supplemented with cottonseed feedlot. It used 100 Nelore cattle, being divided into two groups of 50 animals, which received a cottonseed (CS) in grain form by the diet in the proportion of 15% and the other group was provided with control diet without CS in the feedlot for 88 days. The diets were isoprotein and isoenergetic and concentrate:roughage ratio of 60:40. The animals were slaughter in the end of experimental time and the collection of liver samples for histological analysis. After cooling 24 hours at ± 1°C were conducted evaluation of carcass and major cuts, final pH and collected muscle samples longissimus to carry out the physicochemical analyzes (Color, Cooking Loss, Pigments and Shear Force), chemical composition, fatty acid profile and oxidation. The inclusion of CS in the diet provided animals with higher slaughter weight, daily weight gain, Hindquarter, however, the animals showed reduced carcass yield, forequarter weight and Thin flank, without changing the parameters as rib-eye area and backfat thickness. There was an increase of the yellow values (b*) and moisture with the final pH reduction. There was no influence of the use of cottonseed in relation to histological parameters evaluated in the liver. The cottonseed in the feeding feedlot cattle promoted improvement in animal performance, despite the reduction of the forequarter weight, with appropriate aspects of meat quality, fatty acid profile and conservation.