Numerous epidemiological studies have linked tobacco use with a wide variety of diseases. Strong government-supported anti-smoking campaigns have decreased the prevalence of smoking in many developed countries, including the United States. However, it remains a major public health pariah. In developing countries, such as China, cigarette smoking and other forms of tobacco use continue to increase. If unchecked this will eventually lead to 10 million deaths per year worldwide. Even in the United States, the prevalence of smoking is rising in crucial population groups such as adolescents. Recent advances have made physicians more able to help patients quit smoking, but organized campaigns must be further strengthened to prevent the initiation of tobacco use, especially in the young.