Abstract BACKGROUND: India has the second largest tribal population of the world next to the African countries. About half of the world’s autochthonous people live in India, thus making India home to many tribes which have an interesting and varied history of origins, customs and social practices. The present study was conducted to assess the tobacco use and prevalence of precancerous lesions and oral cancer among Malayali tribes, Yelagiri Hills, Tamil nadu, India. METHODOLOGY The inhabitants of the 14 villages of the Yelagiri hills, who have completed 18years and residing for more than 15years present on the day of examination and who were willing to participate in the study were included. Data was collected from a cross-sectional survey, using a Survey Proforma, clinical examination and a pre-tested questionnaire. An intra-oral examination was carried out by a single examiner using WHO Oral Health Surveys – Basic Methods Proforma (1997). ResultsThe overall prevalence of smokeless and smoking tobacco was 78.8% and 65.2% respectively among 1550 study population. Of those who had the habit of smoking, 26% smoked beedi, 10.9% smoked cigarette, 65% chewed raw tobacco, 18% chewed Hans and 28% had a combination of smoking and smokeless tobacco usage. Around 49.8% of samples were stained positive for precancerous and cancerous lesions of the oral cavity. The highest number of positive samples were from buccal mucosa with 46.2% subjects and 12% for labial mucosa. The reason for practicing these habits were as a measure to combat the cold, relieving stress and body pain after work, and the lack of awareness of the hazards of the materials used. Prevalence of oral mucosal lesions in the study population was due to tobacco usage and alcohol consumption and lack of awareness regarding the deleterious effects of the products used. CONCLUSION Oral cancer is highly prevalent in this Malayali tribes owing to high tobacco consumption rates and habits warranting the cessation center a priority. Also, early detection and screening are vital to attaining better outcomes. Citation Format: Delfin Lovelina Francis. Tobacco use and prevalence of oral premalignant lesions, among Malayali tribes, Yelagiri Hills, Tamil nadu, India [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A092.