The treatment of colon cancer is a significant source of malpractice liability. Physicians are justifiably concerned about malpractice exposure as personal injury attorneys investigate standard and novel malpractice theories and claims. With the general acceptance of the importance of screening for colon cancer, screening for colon cancer is now defined as the standard of care. This has opened up a previously neglected area of malpractice liability. Physicians need to understand the sources of malpractice risk and risk-management strategies related to these sources to reduce their exposure to liability suits in this area. This article outlines these sources evolving from the tort of negligence, including the duty to provide care, practicing below the standards of care, the cause of the harm, and the actual establishment of harm. The concept of vicarious liability and its relationship to the tort of negligence also are discussed. This presentation is developed within the context of a risk-management approach to assist physicians in developing a preventive approach to malpractice liability.