The aim of this study was to evaluate the effects of feeding discarded pecan seeds on intake, performance, carcass components, and quality attributes of meat from ewe and ram lambs. Twenty-four intact ram lambs and twenty ewe lambs 3.56 ± 0.55 months old weighing 18.01 ± 1.86 kg were randomly assigned to 1 of 4 dietary treatments (0%, 3%, 6%, or 9% inclusion of discarded pecan seeds). After 73 days, at 5.28 ± 0.45 months old with an average body weight of 31.76 ± 3.44 kg, animals were slaughtered. The inclusion of 6% and 9% of pecans increased the deposition of Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) in the lean. Dietary treatments did not affect performance, hot and cold carcass weights, cooling loss, pH, lipid stability, WBSF, color parameters, cooking loss, and proximate values. Lower dry matter intake was observed for animals fed 9% of discarded pecans when compared to animals fed no pecans. Meat from animals fed no pecan seeds was more tender and juicer than lamb fed pecans. Sex affected intake, final body weight, average daily gain, fatty acid profile, color, and fat content. Greater levels of margaric and oleic acids were observed in the lean of ewe lambs whereas meat from rams had greater values of linoleic acid. Atherogenicity, thrombogenicity, and hypocholesterolemia/hypercholesterolemia indices were not affected by dietary treatments or sex. Meat from ewes was redder, yellower, and fatter when compared to meat from rams. Results of this research suggest that discarded pecan seeds may be used as an alternative feedstuff in lamb diets up to 9%.