OBJECTIVES: This study aimed to assess mutagenicity biomarkers among Egyptian textile dyeing workers, their alteration with gene polymorphism, and the changes in plasma proteins' expression. METHODS: Using a detailed questionnaire, a comparative cross-sectional study was conducted on 212 workers (106 textile dyeing-exposed group and 106 control group). CBMN-Cyt assay, ERCC2 gene polymorphism, and plasma protein fractions were analyzed in workers' blood samples. RESULTS: Textile dye workers had significantly higher mutagenicity biomarkers than the control group. Mutant ERCC2 genotypes, dye exposure, exposure period, and formaldehyde levels significantly predicted mutagenicity biomarkers' levels. Dye-exposed workers also showed significant changes in plasma protein fractions. CONCLUSIONS: Textile dyeing workers, particularly susceptible genotypes, are at mutagenic risk and have significant changes in plasma protein fractions. Those changes are usually the first detectable response to toxic exposures and can be useful as exposure biomarkers.