The study was carried out to verify the potential anticarcinogenic and antimutagenic activity of garlic and aloe-vera. The ability of aqueous garlic extract and Aloe-Vera gel to inhibit mutation in tester strain of Escherichia coli WP2 uvrA was determined in this study. (The tester E. coli tryptophan auxotroph strain was obtained from Yale University U.S.A.).The spontaneous mutation rate of E. coli WP 2 uvrA was determined in the Ames assay to be 2.2 x 10 -7 . The acridine mutagen showed 333.8% increase of spontaneously reverting colonies of the tester strain. Different concentrations of aqueous garlic extract and aloe-vera gel conferred varying degrees of antimutagenic activities on the tester E. coli WP2 uvrA. Aqueous garlic extract was found to have its highest antimutagenic activity at a concentration of 0.5g/cm 3 (the highest concentration tested) with 81.02% reduction in revertant colonies were observed. 0.1g/cm -3 and 0.25g/cm -3 garlic extract produced 72.16% and 74.82% reduction of revertant colonies respectively. Aloe-Vera gel produced 43.6%, 37.2% and 33.68% reduction in revertant colonies at concentration of 0.5ml, 0.2ml and 0.1ml per plate of the E. coli respectively. From the result obtained in this study, garlic has tremendous potential antimutagenic and anticarcinogenic substances..