Ipriflavone (7-isopropoxy-isoflavone) is a semisynthetic isoflavone derivative from daidzein and prescribed to prevent and treat osteoporosis in postmenopausal women. In the present study, ipriflavone was investigated with regard to their cytotoxic and mutagenic effects using the micronucleus assay (MN) in vivo on cells of bone marrow and peripheral blood of Swiss albino mice and the micronucleus test with the cytokinesis-blocked micronucleus assay (CBMN assay) on human peripheral blood lymphocytes. The studies were performed in mice with three dosages of the drug, 1.71, 8.57 and 42.85 mg/kg bw in single oral exposure, and for two dosages, 5 and 10 μg/mL in the CBMN assay. Ipriflavone, in the dosages tested, did not differ from controls neither in the induction of MN nor induced cytotoxicity to cells in the in vivo test. However, in the CBMN assay, the concentration of 10 μg/mL induced a statistically significant increase in MN formation and decreased cell proliferation, demonstrating to be mutagenic and cytotoxic at this concentration.