Aim: To compare the prevalence of smoking and smoking predictors among adolescents between cities running a healthy city program (HCP cities) and the cities that are not running such a program (NHCP cities) in the Qassim region, Saudi Arabia. Subject and Methods: A cross-sectional survey using a self-reported questionnaire on the prevalence of smoking and smoking predictors among adolescents in Qassim region, Saudi Arabia was undertaken between April and September 2017. Using multi-staged cluster sampling, probability proportionate to the size, we surveyed 364 adolescents from three HCP cites and 769 adolescents from three NHCP cities.Results: The overall prevalence of smoking among school-aged adolescents in Qassim is 5.2% (95% CI: 3.9-6.5). Smoking prevalence among adolescents in the HCP cities is 8.8% (95% CI: 5.9-11.7); while in the NHCP cities it is 3.5% (95% CI: 2.2-4.8). The prevalence of at least one smoker among close friends in HCP and NHCP cities is 67.3% (62.5-72.1) and 72.2% (69-75.3), respectively. The prevalence of at least one smoker in the family of the adolescents in HCP and NHCP cities is 58% (52.9-63.1) and 44.3% (40.8-47.9), respectively. Among the socio-demographic variables, smoking is signi cantly associated with gender (OR: .08) *, age (OR: 1.61) and academic performance (OR: .27). Prevalence of smoking among adolescents is signi cantly higher in HCP cities than in NHCP cities (OR: 3.03; 95% CI: 1.7-5.4).Conclusion: Prevalence of smoking and key smoking risk factors were found to be higher in cities implementing the healthy city program, despite exposure to an anti-smoking campaign being higher in these cities. Given these ndings, we recommend further in-depth evaluation of the program.