Plants are a source of many biologically active products and nowadays they are of great interest to the pharmaceutical industry. In the present study, the mutagenic potential of the Musa paradisiaca fruit peel extract was assessed by the single-cell gel electrophoresis (SCGE) and micronucleus assays. Animals were treated orally with three different concentrations of the extract (1000, 1500, and 2000 mg/kg body weight). Peripheral blood cells of Swiss mice were collected 24 h after treatment for the SCGE assay and 48 and 72 h for the micronucleus test. The results showed that the two higher doses of the extract of M. paradisiaca induced statistically significant increases in the average numbers of DNA damage in peripheral blood leukocytes for the two higher doses and a significant increase in the mean of micronucleated polychromatic erythrocytes in the three doses tested. The polychromatic/normochromatic erythrocyte ratio scored in the treated groups was not statistically different from the negative control. The data obtained indicate that fruit peel extract from M. paradisiaca showed mutagenic effect in the peripheral blood cells of Swiss albino mice.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)