The association between periodontal inflammation and stress is still limited to the evidence from Western countries. The aim of this study was to investigate whether stress was associated with periodontitis among Thai elderly. The cross-sectional study was conducted on 179 elderly aged 60 and over in Khon Kaen, Thailand. A calibrated dentist recorded clinical attachment levels (CAL) using the random half-mouth six-sites per tooth protocol. A face-to-face interview assessed stress level using Self-analyzed and Self-evaluated Stress Test (SSST). A structured questionnaire was used to obtain the information on demographics, medical history, and oral health behaviors. Logistic regression analysis was used to evaluate the association between periodontitis and stress while controlling for possible confounders. The result indicated that stress was associated with periodontitis (tertiary percentage of CAL≥5 mm) with three times higher odds ratio for those who had stress (OR = 3.0; 95 % confidence interval, 1.3 to 7.0) after controlling for all possible confounders. This study suggests that periodontitis is associated with stress in the elderly.