Objective—To study the impact of tobacco advertisements and other social factors on the smoking habits of adolescents in Calcutta, India. Design — Cross sectional, school based survey of students in the IXth and XIth grades. The responses were analyzed by binary logistic regression. Participants— High School students in Calcutta aged 14 to 18 years. Main Outcome Measure — Smoking Status as defined by ever smokers of tobacco products. Results— 1973 students were interviewed (males-73.79% and females-26.21%). Increased tobacco use was associated with older age-groups, male gender, government-run schools, having parents or peers who were smokers, and if the respondent was also a chewer. The likelihood of a respondent being a smoker was 8.5 times greater (95% CI: 5.05- 14.43) if he or she had a smoker friend, and about 4.5 times (95% CI: 2.7-7.4) if he or she had a smoker sibling. In the multivariate model, the parents’ smoking status did not have a statistically significant association with respondent’s smoking status. Television advertisements of tobacco products had no statistically significant association with respondents’ smoking status. Conclusions— The finding of tobacco advertisements not having a significant association with smoking habits among adolescents could be due to the fact that, at the time of this survey, tobacco advertisements were not frequent in the prime channels due to Government regulations. Peer influence had the strongest association with adolescent smoking. It is therefore suggested that the peer influence factor should be considered for anti-tobacco regulatory activities that target adolescent smoking in India.