Garlic is a popular culinary herb that is also used throughout the world as a traditional medicine for the prevention and treatment of disease. Epidemiologic studies have suggested that long-term consumption of garlic reduces risk for certain cancers, most notably stomach and colon cancer. This article summarizes the key findings behind one important mechanism explaining the anticarcinogenic effects of garlic-derived agents in animal models: the inhibition of cytochrome p4502E1 (CYP2E1), with some commentary on other aspects of carcinogen metabolism modified by these unique phytochemicals.