Background: Oral Cancer is a major public health problem in most of the South East Asian countries including Sri Lanka. Use of tobacco in the form of smokeless tobacco and smoking, use of alcohol and betel quid chewing are the major contributory factors for causation oral cancer. The aim of this study was to investigate the prevalence of lifestyle factors responsible for causation of oral cancer and Oral Potentially Malignant Disorders (OPMD) in the Sabaragamuwa province of Sri Lanka. Methods: A cross-sectional community based study was conducted in Sabaragamuwa province by interviewing, then conducting an oral examination, on 1029 subjects over 30 years of age, over a one year period from November 2006. The study protocol included an interviewer-administered questionnaire to gather socio-demographic factors, recording of habits that included areca/betel chewing, smoking, and alcohol consumption. A three-day food diary was obtained, particularly to assess the consumption of tea, fruits and vegetables. The weight and height of residents was taken for calculation of Body Mass Index (BMI). Results: One hundred and two individuals with one or more OPMD were detected among these 1029 subjects. The prevalence of OPMD, weighted according to the estate sector and gender, was estimated as 11.3%. The prevalence of daily betel quid chewing in this study was 53.8%: 15.7% without tobacco and 47.4% with tobacco. The prevalence of individuals who reported consumption of alcohol at least weekly was 13.4%. A significant minority, 31.7%, were under nourished, with a BMI < 18.5. Forty six percent of the males practiced combined habits of betel quid chewing, smoking and regular use of alcohol. Conclusions: This study discloses high prevalence of OPMD and of lifestyle factors for oral cancer in these communities. There is an urgent need for a comprehensive strategy to control the use of tobacco, betel quid chewing and alcohol for prevention of oral cancer.