Physician impairment by substance abuse represents a significant challenge to physicians, patients, and society as a whole. Although data is sparse, the prevalence of alcohol and illicit drug abuse among physicians is probably similar to that of the general population, while abuse of prescription drugs may be more prevalent. From a medicolegal standpoint, these issues are managed mostly at the state level and substance abuse is of increasing interest to credentialling organizations such as hospitals and managed care organizations. A variety of concrete steps can be taken to identify physicians with substance abuse problems and treatment approaches have been designed specifically for impaired physicians. With improved attention to the problem of physician impairment by substance abuse, the well-being of both physicians and their patients can be enhanced.