Forty-four adolescent smokers self-monitored their smoking for 1 week. Four 4 hr each day subjects recorded the person, place, and activity associated with each cigarette smoked. Seventy-one percent of all cigarettes were smoked in the presence of another person. Roughly half of those cigarettes were were smoked with peers. A surprising amount of smoking occurred in the subject's own home, suggesting that the smoking of the subjects is accepted, if not condoned , by their parents. The data generally confirm the social nature of adolescent smoking.