Objective: We assessed the prevalence of moderate and severe periodontitis and its association with social determinants of health in rural and urban population from the State of Chiapas, in Southern Mexico. Material and methods: A cross-sectional population-based study was conducted in 2013 comprising people 20 years and older. The determinants were categorized as proximal (age, sex, indigenous origin, diabetes, smoking, diet), intermediate (level of schooling, occupation, medical and dental care), and structural (type of institution of health care provision, residence area). Periodontal status was assessed using the Periodontal Screening and Recording (PSR) Index. Results: In total, 467 persons (72.4% women; mean age 43.0 years [s.d 14.7]) participated. Of them, 76.5% lived in rural areas and 56.7% were of indigenous origin. Participants with moderate and severe periodontitis had a significantly lower toothbrushing frequency (44.1% and 44.8%, respectively), and poorer oral hygiene (90% and 90.3%, respectively) compared with people without periodontitis (29.4% for toothbrushing frequency and 74.5% for oral hygiene). Moderate periodontitis was associated with poor oral hygiene (OR=2.63) and no schooling (OR=1.86). Severe periodontitis was associated with age (OR=1.05), poor oral hygiene (OR=3.99), no schooling (OR=2.08), and the interaction term of rural area and indigenous origin (RM=5.23). Conclusions: Social determinants of health play an important role in the development of periodontitis. Preventive oral health programs should thus focus on the specific social, economic, and geographical context of the population. Keywords: Oral health, periodontal disease, social determinants of health, indigenous population