Antimutagenicity of flower pleats of Rosa multiflora extract was checked by using “Ames Assay” for direct acting mutagens and those requiring metabolic activation. Two strains of Salmonella typhimurium – TA 98 and TA1535 were used. These strains are histidine requiring mutant strains. When mutagen is added to the culture, the strain is mutated back, there by losing the histidine dependence for its growth. The addition flower extract it prevents the strains to be mutated back to the non-histidine dependence for its growth. For direct acting mutagens sodium azide, ethidium bromide and hydroxyl amine with 1 mg rose flower extract gives 93%, 98%, 95% inhibition in revertant colonies were observed. For mutagen requiring activation, nicotine in tobacco and cigarette gives 97% and 94% inhibition of revertant colonies. These above results indicate that rose flower extract could inhibit the mutagenicity induced by direct acting mutagens as well as mutagen needing activation. These results indicate possible antimutagenic activity of compounds present in rose flower.