In today's medical community, there is growing concern about substance use among physicians, not only because of their own health, but also because of the potential adverse effects on their clinical practices. Physicians affect public health both by treatment and preventive studies and as role models. Prevalence data concerning substance abuse are generally lacking. There is no consensus on the rates of substance abuse being higher among physicians than among the general public. Physicians are less likely to smoke cigarettes and use illicit substances (like marijuana, cocaine and heroin) and more likely to use alcohol and two types of prescription medications--benzodiazepines and minor opioids--compared with their age groups. Doctors are at special risk of developing addiction problems owing to the strain of medical practice, erosion of the taboo against injecting and using opiates, and particularly access to supplies. The most common precipitating factors mentioned are physical pain and illness, usually chronic, with family tragedy such as death of a wife or child next. The third most common factor is an addicted wife. Stress, overwork and marital problems are also mentioned. No data were found about physicians' substance use in Turkey. This article generally aims to review the knowledge on the prevalence of substance use among physicians, the drug of choice, the development of dependence, the treatment and prognosis and to discuss the importance of this issue by evaluating three cases treated at the Alcohol and Drug Addiction Treatment and Research Center (AMATEM), Bakirköy State Hospital for Mental and Neurological Diseases.