The objective of this study was to map quantitative trait loci (QTL) associated with birth weight and weaning weight in Brangus beef cattle. A total of 6 significant QTL over 4 chromosomes were identified. Two QTL were common to both traits. The genome-wide association study (GWAS) results could help us understand the biological process of growth in Brangus. Further analyses are needed to find and validate the casual mutations responsible for these QTL.