Summary Objective: To evaluate and characterize the bruises occurring during the pre-slaughter of beef cattle in a commercial slaughterhouse, and to identify the risk factors involved. Methods: a cross sectionalstudy was conducted on 2,288 carcasses evaluating transport conditions, animal characteristics, severity, extent, and location of the bruises to determine the prevalence and associated risk factors. Results: The bruising prevalence was 84.3%. Sex, weight, stocking density and lairage time were associated with the presence of bruising (p 0.005). Conclusions: results suggest that animal welfare conditions of the evaluated cattle are deficient. Several factors should be improved, such as: training the staff, reducing the lairage time, preventive maintenance for equipment, specialized transportation, sanitary design strategies, and divulgation of sanitary laws, among others.