Abstract Chronic inflammatory diseases and oxidative stress are major risk factors of colorectal cancer (CRC), the third most common cause of death among cancer patients. Although several agents such as antioxidants, plant products and nutritional supplements have been shown to have some chemopreventive effects on colon cancer, none are very effective to completely. Recent studies indicate that a fat soluble analogue of vitamin B1, benfotiamine is an excellent antioxidant and anti-inflammatory. However, the chemo-preventive or -therapeutic efficacy of benfotiamine in preventing CRC is not known. Our hypothesis is that benfotiamine through its anti-oxidant and anti-inflammatory properties could be very effective in preventing CRC. We therefore investigated the role of benfotiamine in the prevention of carcinogenic signals leading to CRC in cell culture as well as murine models of CRC. Our results show that treatment of human colon cancer cells (HT-29 and Caco-2) in culture with benfotiamine prevented the cancer cell proliferation. Further, benfotiamine also prevented the growth of human adenocarcinoma cells (SW480) -induced tumor growth in nude mice xenografts. Our studies also indicate that benfotiamine prevented NF-kB-dependent survival signals and activated caspase-3 dependent apoptotic signals in colon cancer cells. Further, benfotiamine supplementation also suppressed azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation in mice and AOM-induced inflammatory changes such as activation of Cox-2 and iNOS, and carcinogenic changes such as expression of cyclin D1 and β-catenin in mice colons. In conclusion, our results indicate that benfotiamine prevents colon cancer cell growth in culture and nude mice xenografts as well as formation of ACF in AOM-treated mice. Thus benfotiamine supplementation could be used as an excellent chemopreventive agent for the treatment of CRC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2397. doi:10.1158/1538-7445.AM2011-2397