Purpose: The purpose of this study was to examine the effect of school-based preventive education on smoking-related knowledge, attitude and practice of health behaviors among elementary school children at a rural province in Korea. Methods: The subjects were 134 among the 4th -6th graders (exp. = 67, control = 67) from two schools at J province. Education program was conducted in 5-sessions for experimental group. And study instrument for smoking-related knowledge was developed 2-point 15-items (a = .82), for attitude was 3-point 15-items (a = .79), and for practice of health behavior was also 3-point 30-items (a = .86). Data were collected by interview from May 28th to July 10th 2003 and analyzed with the frequency, percentage, x2-test and t-test using SPSS-PC program, Results: The group of having smoking experiences was 14.2% and 52.2% of the subject had smoking family members. The first motive of smoking was curiosity in 78.9% and 36.8% of them started smoking before the third grade. School-based preventive education of smoking were affirmatively effective in smoking-related knowledge (t = 4.14, p = .001), smoking-related attitude (t = 3.654, p = .001), practice of health behavior, on the other hand, was not changed significantly by the education. Conclusion: Based on these findings, the authors recommend that school-based smoking prevention education should be started from lower graders in regular curricular basis and health promotion program for primary school children should be emphasized to lead healthy behavior in collaboration with public and private health sectors in community.