Background: There is increasing evidence linking exposure to environmental tobacco smoke (ETS) at homes to the development of respiratory morbidity including asthma among adolescents. Few studies have addressed this issue in the Middle-Eastern countries including Kuwait. Therefore, this study cross-sectional assessed the prevalence of ETS exposure at home, prevalence of asthma and other respiratory morbid conditions and examined the ETS exposure and personal smoking status as risk factors for asthma among high-school students in Kuwait. Methods: During October 2015, a cross-sectional study design was implemented using a self-administered, modified version of the ISAAC (International study of asthma and allergies in childhood) questionnaire among students enrolled in nine high-schools of Hawally Governorate of Kuwait. Prevalence of ETS exposure, and eczema were computed. Multivariable log-binomial regression models were used to evaluate association between exposures of interest and asthma status. Results: Of 800 invited students, 746 (92.2%) participated, of whom 74.8% were Kuwaiti and 50.1% were female with a mean (SD) age of 16.8 (0.68) years. ETS exposure prevalence at home was 54% and personal current smoking was 12.4%. Asthma prevalence was 20.5%. Furthermore, the prevalence of physician-diagnosed asthma, wheezing during the last 12 months and wheezing ‘ever’ was 16.4%, 20.1% and 26.2%, respectively. Final multivariable log-binomial regression model showed that compared to the adolescents without asthma, adolescents with asthma tended to be current smokers (adjusted prevalence ratio (adjusted PR) = 1.86; 95% CI: 1.37 – 2.53; p < 0.001) or significantly more likely to have had ETS exposure at home (adjusted PR = 1.64; 95% CI: 1.21 – 2.23; p = 0.002). Conclusions: We recorded high prevalence of ETS exposure at home, high prevalence of asthma and identified ETS exposure at home and being a current smoker as strong risk factors for asthma among adolescents. Voluntary household smoking bans may substantially minimize the ETS exposure among adolescents. Additionally, such restriction may inculcate an antismoking attitude and prevent smoking initiation among adolescents. Such efforts are likely to pay dividends in terms of reduction in ETS exposure and associated asthma risk and other smoking-related morbidities in this and other similar settings.