Objectives: The present study aimed to evaluate the validity of a set of self-reported questionnaires for periodontitis for estimating the prevalence of chronic adult periodontitis in the Korean population. Methods: The questionnaire is comprised of a total of 14 questions with four summarized concepts including self-diagnosis of oral status, subjective signs related to oral health, smoking and drinking status, and use of auxiliary oral hygiene devices including scaling. The predictiveness of the measures from these self-reported questions was assessed by logistic regression modeling using receiver operating characteristic (ROC) statistics, sensitivity, and specificity. Results: The sensitivity, specificity, and AUC including all questions were 0.571, 0.768, and 0.781, respectively; the sum of sensitivity and specificity was 1.34. To gain robustness, a simplified predictive model was built with six questions. Its results were 0.536, 0.817, and 0.762 for sensitivity, specificity, and AUC, respectively. The sum of sensitivity and specificity was found to be 1.35. Conclusions: The self-reported questionnaire for periodontitis showed considerable validity, but further study is required to provide optimal validity and predictability.