Tomatoes are the fourth most commonly consumed fresh vegetable and the most frequently consumed canned vegetable in the American diet. There is emerging epidemiology data supporting the connection between increased tomato consumption and reduced risk for both cardiovascular disease and prostate cancer. Here we will summarize the nutrient and the phytochemical content of tomatoes and tomato products, and how these bioactive components might act together to modulate disease development. Recent animal studies have investigated tomatoes, lycopene, and prostate cancer using the N-methyl-N-nitrosourea and Dunning rat models. These animal studies also suggest that diets containing tomatoes may decrease the risk or the progression of prostate cancer. Due to the frequency and the extent of tomato consumption, the supporting epidemiological and animal data, which connect increased intakes with decreased cancer and cardiovascular disease risk, tomato's role in the American diet is of undeniable importance as part of a healthy diet.