Color Index (C.I.) Disperse Red 1 (DR1) is a widely used textile azo dye found in rivers. As it may not be completely removed by conventional treatments, humans can be exposed through drinking water. Studies have supported in vitro toxicity and mutagenicity of commercial DR1. This study aimed to investigate the mutagenic and toxicogenomic effects of commercial DR1 in multiple tissues/organs of Swiss male mice. For that, animals were orally exposed to the dye (by gavage), at single doses of 0.0005, 0.005, 0.5, 50, or 500 mg/kg bw. The two lowest doses were equivalent to the ones found in two Brazilian rivers receiving influx of textile discharges. Cytotoxicity, micronucleated cell frequencies (for all doses tested), primary DNA damage (comet assay), and gene expression profiling of (0.0005 and 0.005 mg/kg of bw) were investigated 24 hr after animal exposure to commercial DR1. Data showed increased frequencies of micronucleated polychromatic erythrocytes in bone marrow cells after treatment with 0.5 and 50 mg/kg bw. At 0.005 mg/kg bw, commercial DR1 induced an increase of primary DNA damage in liver, but not in kidney cells. Additionally, upregulation of genes involved in the inflammatory process (IL1B) (0.0005 and 0.005 mg/kg bw) and cell-cycle control (CDKN1A) in liver cells, and apoptosis (BCL2 and BAX) in leukocytes (0.005 mg/kg bw) were also detected. In conclusion, the commercial DR1 was genotoxic (chromosome aberrations and primary DNA damage) and modulated gene expression in mice, and such effects were dependent on the doses and tissues analyzed. Environ. Mol. Mutagen. 59:822-828, 2018. © 2018 Wiley Periodicals, Inc.