Objective This study estimated the association between stress and periodontitis. Materials and methods A cross-sectional study was conducted with a sample of 621 individuals. Information about individuals was obtained through a questionnaire. Stress was evaluated using the Perceived Stress Scale. The diagnosis of periodontitis was based on a complete periodontal examination including clinical attachment level, probing depth, and bleeding on probing. Prevalence ratios (PR), crude and adjusted, and their respective 95% confidence intervals (95%CI) were estimated by Poisson regression analysis. Results In the final sample, 48.47% (301) of the individuals were classified as having stress, of which, 23.92% (72) had the diagnosis of periodontitis. Association measurements between stress and probing depth ≥ 4 mm (PR adjusted  = 1.28, 95%CI 1.04 to 1.58), stress and clinical attachment level ≥ 5 mm (PR adjusted  = 1.15, 95%CI 1.01 to 1.31), and stress and periodontitis (PR adjusted  = 1.36, 95%CI 1.01 to 1.83) showed that the frequency of these outcomes among those exposed to stress was 15–36% higher than those without the condition of stress, after adjustment for age, sex, schooling level, current smoking habit, pulmonary disease, and body mass index. Conclusions The findings showed positive association between exposure to stress and the presence of periodontitis, reaffirming the need to prevent and control stress. Clinical relevance Although there are limitations in this study, the results showed that an association exists between stress and periodontitis, signaling the necessity of a multidisciplinary attention when considering the psychological status in the management of oral and general health conditions of the individual.