The legal consequences of excessive sleepiness may impact patients, their physicians, and the public at large. Individuals with daytime sleepiness and/or known or suspected sleep disorders need to take precautions at work or when driving to ensure that they do not pose a risk to themselves or others. Physicians should inquire about excessive sleepiness or other symptoms of sleep apnea in any patient who drives, but especially in patients who are commercial vehicle drivers. Physicians and healthcare workers need to be aware of the accident risks associated with sleep disorders and the legal implications around this in their particular jurisdiction. The development of new guidelines and medical standards in the transportation industry will eventually have an impact on physicians, employers and drivers alike. Legislators must continue to work with practitioners and scientists to balance adequate protection of the public interest with individual rights.