Objectives: Identify the determinants of periodontitis in a rural Indian population aged 35-44 years. Basic Research Design: Case-control clinical and questionnaire study in a cluster sample of 50 villages. Methods: A total of 3000 persons were screened for the presence of periodontitis using the CDC case definition in full mouth examination. Equal numbers of cases (604 persons with periodontitis) and controls (604 without periodontitis) were recruited and interviewed with a piloted questionnaire. Univariate and multivariate analysis estimated crude and adjusted odds ratios (aOR) respectively with 95% confidence limits. Results: Six factors were determined by multivariate analysis to predict periodontitis: education less than or equal to twelve years of schooling (aOR=2.51, 95% CI=1.18-5.34), alcohol consumption (aOR= 1.7, 95% CI=1.16-2.49), consuming a non-vegetarian diet (aOR=1.38, 95% CI=1.08-1.76), not drinking milk (aOR=1.7, 95% CI= 1.29-2.24), not using a toothbrush for cleaning of teeth (aOR=2.98, 95% CI =1.71-5.21) and not cleaning teeth at least once a day (aOR=2.13, 95% CI=1.58-2.87). Conclusion: Risk factors for periodontitis in a rural Indian population were identified. Further studies should validate these findings and appropriate recommendations should be developed to decrease the prevalence and burden of periodontitis in this population. Keywords: Case control study; epidemiology; periodontitis; risk factors; rural.