Baccharis dracunculifolia De Candole (DC) (Asteraceae) is indigenous throughout southeastern Latin America and is used by local people in traditional medicine. This plant is known to be the source of resin for the highly valued Brazilian green propolis. As no information is available on the safety of high doses of B. dracunculifolia extract, we evaluated the mutagenic potential of high doses of this plant extract in vivo on peripheral blood cells of Swiss mice using the comet assay and the micronucleus test. The extract was administered by gavage at doses of 1000, 1500 and 2000 mg/kg body weight. Peripheral blood cell samples were collected 4 and 24 h after treatment for the comet assay (genotoxicity assay), and at 48 and 72 h for the micronucleus test (clastogenicity assay). The B. dracunculifolia extract was devoid of clastogenic/genotoxic activity at all doses.