Objective: To determine the distribution of oro-mucosal lesions in patients of Maharishi Markendeshwer College of Dental Sciences and Research, (MMCDSR), Mullana. Further to identify sex predilection and different sites which are more susceptible to different oro-mucosal lesions. Materials and methods: A hospital based retrospective study was carried out from 1st January 2007 till 31st December 2009 at (MMCDSR), Mullana. A total of 451 biopsy reports were studied. Distribution and prevalence of oro-mucosal lesions among the data were analyzed using SPSS software package version 13. Results: There was no mention of habits in the biopsy reports of 85.4 % (385 patients) of the subjects. Out of the 66 subjects whose habits were mentioned, 71.2 % (47 patients) used to smoke tobacco in one form or the other. 21.2 % (14 patients) used to chew tobacco, 4.5 % (3 patients) of the subjects were in the habit of both smoking and chewing tobacco. More percentage of females 53.1 % were present in the age-group of 11-20 years as compared to males 46.9 % whereas in all other age-groups males were more in number. Regarding the distribution of oral lesions in the oral cavity, buccal mucosa was the common site for the presence of potentially malignant disorders in 16.8 % of the subjects and it was also the most common site for all the lesions. Conclusion: Lesion prevalence differed significantly by age, sex, and tobacco use. Individual demographic details such as age, gender, occupation, food habits, other deleterious oral habits, religion and oral hygiene measures should have a provision in biopsy request sheet and should be duly filled which will help in identifying risk-groups. Community programmes should be taken for public health to get them screened for any oral-mucosal lesions by availing pathological lab facilities.