Introduction: Alcohol consumption and smoking are two strongly related adverse habits which tends to peak between the age group of 18-25 years and college students in these age group are at high risk of having these habits. Aim: The present study aims to determine the knowledge, attitude and practice of alcohol intake and smoking among the undergraduate students of a private dental college in Ghaziabad, India. Materials and methods: A questionnaire based cross-sectional study was conducted among a sample of 350 undergraduate students. A self-administered questionnaire was used to collect the data from the participants. The data analysis was performed using Statistical Package for Social Sciences (SPSS) 18.0 (SPSS Inc., Chicago, IL, USA). Descriptive and analytical statistics were done and the level of confidence was set at 95%. The level of significance was set at p<0.05. Results: Among the total sample of 350 students, majority were females (55.72%) and belongs to the preclinical group (50.85%).Most of the students irrespective of gender correctly identified both liver disease and cancer as a major outcome of alcohol consumption and smoking. There were no significant differences between the gender and their knowledge regarding smoking and alcohol consumption while the year of study found a significant relation. Conclusion: The study findings concluded that the overall knowledge of undergraduate dental students on health implications of excessive consumption of alcohol and smoking was adequate although their influence on certain diseases was lacking. Keywords: Knowledge, attitude, practice, alcohol and smoking, students