Objectives: The rate of adolescent smoking is important because lead to adult smoking. And early onset of smoking is associated with chronic disease in adult life. The purpose of this study is to describe the smoking status of adolescents and identify the risk factors for smoking in each school. Methods: We selected the participant schools that are located in Yang-cheon Gu, Seoul, Korea, considering the social economic status. The subjects were included 719elementary school students,1,251 middle school students and 1,513 high school students. Self-reported questionnaires were administrated between December 16 and December 24 , 2002. Students were informed in writing that the survey was voluntary. The response rate was 98.7, 81.1 and 95.4 in elementary, middle, and high school, respectively. Results: The results of this study were as follows: 1) Students who have attempted to smoke were 8.8% in elementary school, 29.3% in middle school and 35.0% in high school. 2) The current smokers were 2.0%, 7.9% and 11.5% in elementary, middle and high school, respectively. 3) In elementary school, smoking of mends and physical health were significantly predicted the attempt to smoke. Stress, smoking of mends, alcohol, and binge drinking were associated with the attempt to smoke of middle school students. In high school, the attempt to smoke was related to gender, maternal education, depression, school performance, smoking of brothers, smoking of mends, alcohol, and binge drinking. 4) Current smoking was associated with smoking of mends and binge drinking in middle school and gender, school performance, smoking of brothers, smoking of mends, alcohol, and binge drinking in high school in multiple logistic regression. Conclusion: There is a need for health education and specific strategies to help adolescents prevent from smoking. Smoking prevention programs which include risk-taking behavior such as alcohol, method of copying with stress, and supporting environment were required.