Genotoxic and carcinogenic effects have been attributed to disinfection by-products (DBPs), but few studies on the genotoxicity of hydroxyfuranones (HFs) exist. This limited information gives special relevance to obtaining new data on their potential genotoxic activity, mainly by in vivo test approaches. In this study we present the results obtained with two HFs, namely mucochloric acid (MCA) and mucobromic acid (MBA), in the in vivo wing somatic mutation and recombination test in Drosophila, which detects both somatic mutation and recombination, two mechanisms of especial relevance in cancer processes. The results showed that none of the three categories of mutant spots recorded (small, large, and twin) increased significantly by the treatments, independently of the concentrations tested. This indicate that the two HFs evaluated do not exhibit genotoxic activity in the wing spot assay of D. melanogaster. These in vivo results contribute to increase the scarce genotoxicity database on the DBPs.