Efeito da dieta contendo caroço de algodão no desempenho, características quantitativas da carcaça e qualitativas da carne de novilhos Nelore confinados. The purpose of this work was to evaluate performance, quantitative characteristics of the carcass and qualitative characteristics of the meat of confined castrated Nelore males. Animals were confined with four diets containing 80% concentrate (dry matter): a control diet devoid of whole cottonseed (CA0), a diet containing 10%(CA10) or 20% of whole cottonseed (CA20) and a diet containing 20% of whole cottonseed heated in a climate chamber (CA20H). At the end of the experimental period, there were no differences between treatments for dry matter intake. However, the average daily gain, live weight and feed efficiency were greater for animals fed the whole cottonseed-enriched diets, whit no difference among diets when compared to control. Values documented for blood urea-N were significantly higher for treatments containing whole cottonseed, while glucose and total serum protein did not differ. Carcass yield, loin eye area, subcutaneous fat thickness, renal and pelvic fat, warm carcass weight and cold carcass weight, weight of the liver and values of carcass pH were not significantly different. Differences were noted only for carcass temperature 1 hour and 24 hours after slaughter, lower for CA0 treatment. There were no significant differences for dry matter content and ethereal meat extract. No differences were found between total cooking losses and meat tenderness between 7 and 14 days of maturing, as verified by shearing forces. Only time effect was noted, with meat matured for 14 days presenting with increased tenderness and less total cooking losses. Sensorial analysis of the Longissimus dorsi did not show differences among treatments for typical odor, juicyness and typical or off-flavour. No statistical difference was found for total saturated fatty acids and omega-3, or the relations between total unsaturated or monounsaturated and saturated fatty acids. However, animals fed whole cottonseed-enriched diets had higher concentrations of polyunsaturated fatty acids and omega-6 and lower concentrations of monounsaturated fatty acids in the Longissimus dorsi. Whole cottonseed can be