Background and objective: Smoking is a common health problem which has involved many young people in the society. This study was done to assess the effect of a health education program considered based on the health belief model (HBM) to improve smoking preventive behaviors among 3rd-grade high school students in Nowshahr city, north of Iran.

Materials and methods: This study was a quasi-experimental study in was performed on 280 male students of 3rd-grade high schools of Nowshahr city; they were randomly allocated into experimental and control groups. Data was collected through a researcher-made questionnaire including 40 questions based on health belief model (perceived susceptibility, perceived severity, perceived benefits and perceived barriers to smoking, and cues to action) and preventive behaviours of smoking. After data collection in the first phase, health educational intervention was implemented in the second phase. Data was analyzed using SPSS 18 with descriptive and inferential (Chi Square, independent t and pair t) tests.

Results: The mean score of all HBM constructs in experimental group after applying health educational intervention compared with before the implementing the intervention was significantly different (p ˂ 0.05). Moreover, the mean score of all parts of HBM constructs after the intervention was significantly increased in the experimental group compared with the control group (p ˂ 0.05).

Conclusion: Implementing smoking preventive actions is effective on smoking preventive behaviors among high school students. Therefore, smoking prevention programs should be started before and during the high school period.

Paper Type: Research Article.