Forty lambs with 90 +/- 5 days of age; 24 +/- 3 kg initial BW; were confined in a feedlot for 60 days and assigned two different diets, without or with soy lecithin. The animals were slaughtered, and the carcasses were kept in a cold chamber for 24 h, at 2 degrees C, and were measured for carcass yield, chemical composition of the meat, lipid oxidation and fatty acid profile. The experimental design was completely randomized, data were analyzed using SAS, and compared with the means by the Student Test at 5% probabilities. The use of soy lecithin improve daily weight gain (kg/d, P < 0.05) and reduced hot and cold carcass yield (P > 0.05), but it did not alter other carcass characteristics with pH, temperature, loin area, subcutaneous fat thickness. The moisture, protein, ethereal extract and mineral of meat has not been altered by the soy lecithin (P > 0.05). The results was same for lipid oxidation (P > 0.05). In the fatty acid profile, only C17:1c9 and C18:2t acids were altered (P < 0.05). The study indicates that soy lecithin can be used safely in animal feed as it does not negatively affect the quality of the meat and carcass of the animal, ensuring the production of food safety for the consumer.