Abstract: Nine Rhamnus alaternus extracts were tested for both mutagenic and antimutagenic effects using the Salmonella microsome assay with the two tester strains Salmonella typhimurium TA98 and TA100. None of these extracts was mutagenic. The antimutagenicity of the same extracts was also tested against the S9-dependent mutagen, Aflatoxin B1 (AFLB1) (10 μg/assay). Total Oligomers Flavonoids (TOF), ethyl acetate and methanol extracts showed the strongest inhibition of the mutagenicity induced by AFLB1 in both TA98 and TA100 assay system. In addition to antimutagenic activity, the TOF and the ethyl acetate extracts showed an important free radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazyd (DPPH) radical. These results suggest the future utilization of these extracts as additives in chemoprevention studies.