Colorectal cancer, arising from colorectal adenoma, remains a common cancer and cause of death in men and women. Currently there are many developments in modern surgery and chemo-radiotherapy, including screening and prevention programmes, aimed to increase survival time. This article briefly reviews the role of chemopreventive agents in colorectal cancer. Regular aspirin use reduces the risk of sporadic colorectal adenomas. Sulindac and celecoxib (nonsteroidal antiinflammatory drugs, NSAIDs) reduce the number and size of colorectal adenomas in patients with familial adenomatous polyposis. Folate, calcium, hormone-replacement therapy, vitamins, antioxidants and dietary fiber intake might contribute to the prevention of colorectal adenomas and carcinomas; however further randomized controlled trials are needed to support this theory.