Oxidative stress is associated with colon carcinogenesis including aberrant crypt foci (ACF) formationand it plays an important role in pathophysiological changes in cancer cells. The aims of this study were toinvestigate the effects of dietary unpolished Thai rice (UTR) on ACF formation and dysplastic progression inazoxymethane (AOM)-treated rats. Anti-cancer efficacy of UTR regarding apoptotic induction and oxidativeredox status in human colon cancer (CaCo-2) cells was also investigated. Rats given 20% and 70% of UTR inthe diet showed significantly and dose-dependently decreased total number of ACF. UTR treatment also wasstrongly associated with the low percentage of dysplastic progression and mucin depletion. In addition, wefound that UTR significantly induced cancer cell apoptosis, increased cellular oxidants, and decreased the levelof GSH/GSSG ratio in CaCo-2 cells. Our study suggests that UTR supplementation may be a useful strategyfor CRC prevention with the inhibition of precancerous progression, with induction of cancer cell apoptosisthrough redox alteration.