Background: Smoking is the leading cause of preventable diseases and premature death. Smoking can increase the risk of cardiovascular disease, respiratory disease and 10 different form of cancer. Starting smoking at a tender age causes more problems. Health care professionals who smoke are less likely to recognize their role as health educators and they are less likely to effectively counsel smokers on quitting. Therefore it is necessary to reduce the number of smokers and harm done to the society. Objectives: to assess the knowledge on hazards of smoking among health care and non health care students, to identify the attitude towards smoking among health care and non health care students and to compare the knowledge and attitude on smoking among health care and non health care students. Methods: Non experimental descriptive comparative survey design and a purposive sampling technique for data collection was used.After obtaining informed consent from each of the participants, Personal profile were collected using a Structured Questionnaire, a 4 point Likert Scale was used to assess the attitude on smoking and Semi Structured Questionnaire was used for assessing the Knowledge on hazards of smoking among 100 health care and 100 non health care students in selected colleges of Gangtok, East Sikkim. Result: The findings of the study reveals that among health care students, 24% had good knowledge, 76% had average knowledge and 100 % had favorable attitude towards smoking. Whereas among non–health care students, 8% had good knowledge, 87% had average knowledge, 93% had favorable attitude and 7% had unfavorable attitude towards smoking. There was a significant difference in the knowledge on hazards of smoking and their attitude towards it between health care and non-health students. Conclusion: Knowledge on hazards of smoking and attitude towards it among the health care students were found to be adequate whereas it was found inadequate among the non-healthcare students. Therefore disseminating knowledge and awareness on hazards of smoking with the help of pamphlet among the non-health care students was found to be fruitful.