This study aimed to investigate the relationship between pre-slaughter factors and major causes of total or partial carcass condemnation in a broiler slaughterhouse under federal inspection. Data on total and partial carcass condemnations between 2018 and 2020 were collected from 10 broiler farms supplying a slaughterhouse located in northern Paraná State, Brazil. The total sample comprised 2,562,642 birds. The pre-slaughter factors analyzed were age at slaughter, stocking density, weight at slaughter, feed conversion, and mortality.Associations between causes of condemnation and pre-slaughter factors were analyzed using a generalized linear model with negative binomial distribution, a generalized linear model with quasi-Poisson distribution, and a generalized linear mixed model with Poisson distribution. Total carcass condemnations were mostly due to repugnant appearance (48.67%) and arthritis (26.56%), whereas partial carcass condemnations were mainly due to arthritis (31.02%), bruising (27.97%), and myopathies (15.18%). Mean age and stocking density were the preslaughter factors that most contributed to increasing total and partial condemnation rates, indicating that reducing stocking density and age at slaughter might be important strategies for minimizing economic losses associated with carcass condemnation.