Drosophila melanogaster is a useful model for genetic studies, including those aiming to detect genotoxicity. The SMARTs (somatic mutation and recombination tests) in Drosophila are in vivo short-term assays that assess genetic damage induction in somatic cells of adult fl ies after larval exposure. They are less onerous than other Drosophila tests (the germinal ones) and are very sensitive, specifi c, and accurate. All of them are based in obtaining heterozygous offspring with particular phenotypes, in which the occurrence of genotoxic events in proliferating (imaginal disk) cells leads to an alteration of this phenotype, which is manifested as mutant spots easily detectable in a normal phenotypic background. Among the various SMARTs available, in this chapter, we will discuss the wing-spot assay ( mwh/fl r 3 ) and the eye-spot white/ white + ( w/w + ) assay, provide a comprehensive overview, introduce the principles of the assays, and provide the details to properly conduct both of them.