Background: The act of someone who is not the intended “active” smoker inhaling tobacco smoke, also known as secondhand smoke (SHS) or environmental tobacco smoke (ETS), is known as passive smoking. It happens when tobacco smoke enters an area and is inhaled by those who are present in that area. Several of the same problems caused by direct smoking are also caused by passive smoking, such as lung cancer, cardiovascular ailments, and respiratory disorders. Objectives: To investigate the influence of active and passive smoking among adolescents upon lung capacities. Methods of the study: A quantitative study design comparative Study was Carrie out in order to achieve the stated investigation of the influence of passive and active smoking on adolescents upon lung capacities through lung function test by spirometer. The study begin from January 7, 2022 to June 16, 2022 in Karbala city Results: the study results for demographic data among passive and active study subject indicate most of age is (18-19) within age groups of male and females. Also, the majority of the study sample for class are within sixth class and the majority for students for body mass index (BMI) are normal among passive and active smokers, also the parameters depict the clinical data for study sample that indicate the majority of the study sample does not have chronic diseases such as (hypertension, diabetes mellitus, and cardiovascular disease) among passive and active smoker, also depict that the study results about the ratio between forced expiratory volume at one second (FEV1) and force vital capacity (FVC) that indicate the majority of the study sample are predict for respiratory disease among active rather than passive. Conclusions: active smokers found to be predictable or susceptible for risk factors of respiratory disease according to indicater (FEV1 / FVC %) on the opposite side passive smokers are less susceptible for risk factors of respiratory disease. Recommendation: Encourage clients to do breathing exercises and walk in an area with fresh air daily to improve lung capacity, provide programs that show and highlight the dangers of active and passive smoking, recommends that all physicians ask all their clients about tobacco and cigarettes use, and advise them to stop if they do.