BackgroundThe prevalence of hookah is increasing worldwide and in all age groups, especially among women. Therefore, this study was conducted to determine the effect of web-based educational program in the prevention of hookah smoking among girls in Kermanshah, Iran, using theory of planned behavior (TPB).MethodsThis study was a randomized controlled trial performed on 110 adolescent girls in Kermanshah City in 2020. Multistage random sampling was used in this study. The data collection tool included a researcher-made questionnaire. Designed intervention was implemented for the intervention group in 5 educational sessions according to analysis of pre-test results. Data were collected 3 months after the end of the training intervention. Data analysis was carried out using SPSS software.FindingsThe presented interventions significantly improved the structures of attitude (P < 0.001), subjective norms (P < 0.001), and intention (P < 0.001) in the intervention group compared with the control group. However, the difference between perceived behavioral control score in the two groups was not significant (P = 0.131). There was also a significant difference in reducing the behavior of hookah smoking between the intervention and control groups after the educational intervention.ConclusionUsing web-based interventions is a good educational strategy for prevention of hookah smoking in adolescent girls.