Tobacco use among school children and adolescents is an increasing problem world-wide, particularly in the developing countries. A cross-sectional observational study was carried out in six co-educational high schools in Kolkata, West Bengal among 526 students of 15-19 years to determine the prevalence of smoking and to find out any difference among the smokers and non-smokers regarding factors related to family relations, peer group and personal characteristics. The overall rate of smoking was found to be 29.6%, mean age of initiation of smoking was earlier in males. Among smokers 75% students started smoking by 15 years. Smoking of father and peer group, family conflict and pornography addiction were found to have significant association with smoking of students. Early school health based interventions addressing these factors might help in effectively tackling this problem.