We compared the effect of 26 types or groups of vegetables and fruit on the risk of cancer using data from two case-control studies that included 1,225 cases of cancer of the colon, 728 cases of cancer of the rectum, 2,569 cases of cancer of the breast, and 5,155 hospital controls interviewed between 1991 and 1996 in six Italian areas. Most vegetables were inversely associated with cancer of the colon and rectum, whereas only carrots and raw vegetables lowered breast cancer risk. High fruit intake was associated only with a reduction of rectal cancer. Different contents of sugar, fiber, carotenoids, and folic acid in fruits vs vegetables plus the concurrent consumption of oil with vegetables may partly explain these findings.