Colorectal cancer is an important, and often dreaded, consequence of long-standing UC and Crohn's colitis. Surveillance colonoscopy, despite its limitations, is beneficial for detecting earlier stage cancers and, probably, mortality reduction. Agents such as anti-inflammatory medications, folic acid, and ursodeoxycholic acid show promise for chemoprevention in this disease. Future research will help to define better the natural history of dysplasia in IBD, and to determine how molecular approaches may be integrated into surveillance programs to reduce CRC risk.