FD&C Red No.3 (erythrosine) has been used as a dye in foods, drugs and cosmetics since its approval by the US Department of Agriculture in 1907. In 1977 the Certified Color Manufacturers' Association (CCMA) initiated studies on FD&C Red No.3 including chronic toxicity and carcinogenicity studies in rats and mice. Data from the CCMA chronic studies revealed an increased incidence of thyroid follicular cell hyperplasia and adenomas in male rats that received 4% FD&C Red No.3 in the diet (2464 mg/kg/day) during life-time (30 months) following in utero exposure. In this report, results of published studies on the mutagenicity of FD&C Red No.3 are critically reviewed. Additional mutagenicity tests including Ames Salmonella/microsome assay, L5178Y TK+/- mouse lymphoma assay, mouse micronucleus test and mitotic recombination assay with yeast Saccharomyces cerevisiae strain D5 are described. These test results together with the literature review indicate that FD&C Red No.3 can be considered non-mutagenic across several genetic endpoints including gene mutation, chromosome aberrations, primary DNA damage and cell transformation. The results of the genotoxicity assessment generally exclude FD&C Red No.3 as a genotoxic initiator and suggest that some other mechanism is responsible for the increase in tumors.