Introduction: Tobacco causes various adverse effects such as oral precancer, cancer, chronic obstructive pulmonary disease, hypertension, peripheral vascular disease, and myocardial infarction, etc. Passive smoking is inhalation of smoke called second-hand smoke or environmental tobacco smoke by persons other than active smoker. Tobacco smoke contains thiocyanate (SCN), which can enter the human body through ingestion or inhalation. Various adverse effects have been reported due to increased serum SCN concentration. Serum and salivary SCN levels have been used to evaluate toxicity among active smokers. However, screening of exposure to tobacco among passive smokers needs to be studied. Estimation of salivary SCN can be a useful indicator for the same. Aim: Estimation and comparison of the salivary SCN levels in active and passive smokers. Materials and methods: Twenty passive smokers and 10 active smokers aged between 18 years and 21 years, with the history of minimum of 1 cigarette/day, for a minimum period of 3 months were included in the study. Active smokers with history of chewable tobacco and passive smokers with history of chewable/nonchewable tobacco, patients under nitroprusside therapy, alcohol consumption, and any systemic diseases were excluded from the study. Whole unstimulated saliva was collected and was stored at −20°C. Salivary SCN levels were estimated. Results: Study shows increased salivary SCN level in active and passive smokers with increased number of cigarettes and duration of exposure. Study revealed positive correlation with salivary SCN level and increase in number of cigarettes and exposure among passive smokers. Sensitivity and specificity are 70% and 80%, respectively. Conclusion: Salivary SCN can be used for screening of passive smokers for the exposure of tobacco to monitor their associated toxicity. Clinical significance: Passive smoking is inhalation of smoke called second-hand smoke or the environmental tobacco smoke by persons other than active smoker. Tobacco smoke contains SCN, which can enter the human body through ingestion or inhalation. Various adverse effects have been reported through increased serum SCN concentration. The present study significantly indicates that passive smokers are at equal risk to tobacco smoke as active smokers.