Many studies have explored variability to select cattle with high genetic potential for economic interest traits. Genetic variability is a powerful tool to improve production indexes in cattle, as it also is associated with variations in meat and carcass quality traits. We made a Genome-Wide Association Study of beef cattle of Bos indicus origin, in particular Nelore animals, to identify regions and genes associated with carcass quality, by examining phenotypic and genotypic data from 909 animals. Several genes in associated regions were observed to have above 1% of the portion of explained genetic variance explained: for hot carcass weight, genes LRGUK, TRIM24, SVOPL, TEX37, CA10, OXSR1; for ribeye area, genes TWIST2, SFXN1, CMYA5, CPQ and MRS2; for backfat thickness, genes OR2S2, 5S_rRNA, LOC100299372, LOC523083, LOC532403, LOC613441, SNORA69 and ITGA9; and for marbling, genes EMCN, LNX1, EIF5, SNORA28 and DSC3. The various genomic regions associated with small effects show the complexity of these phenotypes and that they do not depend only on the effects of a few genes to determine their variations.