OBJECTIVES: This study was designed to provide basic information for smoking prevention education for middle school students by examining their knowledge and attitudes toward smoking. METHOD: A survey was conducted in this study on 1,250 students from 12 middle schools in the six educational bureaus in the Busan region. Results from the preliminary survey showed that the reliability of the instruments for knowledge and attitudes toward smoking were 0.84 and 0.86, respectively. The data for this study were collected for 20 days from Dec. 1 to 20, 2000, and then statistically analyzed with the SAS program using frequency, percentage, mean and standard deviation, and two-way ANOVA. RESULTS: (1) The highest frequency of responses found that both male and female students did not smoke at all. Among 170 students who had experiences of smoking, 66.5% reported they tried smoking because of curiosity, and 38.2% reported they first smoked during the 2nd grade of middle school and 1.2% during 4th grade of primary school. (2) In scores on smoking knowledge, the item with the highest score in both male and female students was one that they had no smoking experiences et al, followed by smoking experiences in the past and experiences of regular smoking. (3) In scores on attitude toward smoking, both male and female students were scored as the highest at the item that they had no smoking experiences et all, followed by the item that they smoked in the past and that they experienced regular smoking. (4) There was no significant correlation between knowledge and attitude toward smoking among the whole subjects (r=0.09, P=0.00). With regard to regular smoking experiences among the male and female students at the 3rd grade of middle school, there was a relatively high correlation between knowledge and attitude toward smoking among them (r=0.57, P=0.00; r=0.56, P=0.01). CONCLUSION: Students who had never smoked or smoked only in the past need smoking prevention education consistently. Particularly, for those who were regular smokers, not only individualized but also organized in small size groups, they need an intensive educational program on the basis of counseling to reduce smoking and to put in practice smoking cessation.