Physicians play an important role in the driver licensing process because drivers, most frequently older ones, acquire diseases that impact their ability to operate a motor vehicle safely and because patients, their families, and regulatory agencies rely on them for diagnosis and treatment. It is now fairly clear that moderately and severely demented patients cannot drive safely. However, the issue of whether the mildly or very mildly demented patient can drive safely has not been fully resolved, although substantial evidence is emerging that most of these individuals have a higher accident risk than their healthier aged counterparts. Physicians, most commonly primary care physicians, will be encountering growing numbers of aged driving persons, particularly those over 70, who are at the greatest risk for developing age-related brain diseases in addition to other physical ailments. It is now evident that the cognitive impairment that accompanies these conditions can have a dramatic impact on driving ability, and recent legislation in a growing number of states (e.g., California and Utah) requires physician reporting of cognitive impairment for driving purposes. Thus, what should the physician do with regard to the ''at risk'' older driver to ensure good medical practice while maintaining a sound ethical and legal posture toward the patient, his family, and the stale and its agencies? This article reviews the status of physicians with regard to the cognitively impaired driver, particularly in states where the law mandates reporting of such individuals. The problem of timely and effective screening for the cognitively impaired driver is raised, and alternative approaches to the screening process are discussed.