The objective of this study was to identify genomic regions associated with beef fatty acid profile (FA) in Nellore males finished in feedlot using the single-step method. A total of 1,616 genotypes and 963 phenotypes were used. Animals were genotyped using the high-density BovineHDBeadChip panel, which contains 777,962 SNP markers distributed throughout the genome. Quality control (QC) criteria were: i) SNPs with minor allele frequency ≤5%, call rate ≤90% (CR); ii) Only samples with CR ≥90% were considered. A total of 470,007 SNPs and 1,556 samples remained in the data set. The FA profile was measured in Longissimus thoracis muscle using a gas chromatography, with a 100 m capillary column. The following FA were analyzed: total saturated FA (SFA), total monounsaturated FA (MUFA), total polyunsaturated FA (PUFA), omega-3 (n-3) and omega-6 (n-6). Contemporary groups (CG) were defined as farm, year of birth, and yearling management group. Variance components estimation model included random additive direct genetic effects, fixed effects of CG, and animal’s slaughter age as a covariable (linear and quadratic effect). For SFA, MUFA, PUFA, n-3 and n-6, a total of 31, 19, 40, 6 and 6 genomic regions that explain 1% or more of the additive genetic variance were found, respectively. Preliminary studies showed that many of these regions were not previously detected in other cattle breeds. Genes like PRKAR1A (protein kinase), ELOVL5 (fatty acid elongase 5), FASN (fatty acid synthase) and SCD (esterol-CoA desaturase) were also identified. This study found several genomic regions associated with meat fat acidy profile in Nellore cattle that can be used for further studies to contribute for the production of healthier meat. This work was supported by Sao Paulo Research Foundation (FAPESP) grant #2009/16118-5 and grant #2011/21241-0.