Recent research has confirmed that many common foods contain nonnutritive components that may provide protection against chronic disease including some forms of cancer. These naturally occurring compounds, which possess anticarcinogenic and other beneficial properties, are referred to as chemopreventers. The predominant mechanism of their protective action is due to their antioxidant activity and the capacity to scavenge free radicals. Among the most investigated chemopreventers are some vitamins, plant polyphenols, flavonoids, catechins, and some components in spices. The majority of chemopreventers are available in and consumed from vegetables, fruits, grains, and tea. Various naturally occurring chemicals in garlic, soybeans, tea, and red wine appear to be responsible for the beneficial effect of these commodities on several chronic diseases. This article will review some recent studies in the search for the beneficial effects of dietary chemopreventers on human health.