The purpose of this prospective cohort study was to investigate whether Type D personality was related to periodontal disease in Japanese university students. Among students (n = 600) who were interested in receiving oral health examinations, logistic regression analysis showed that the risk of developing periodontal disease during a 3-year period was associated with body mass index >= 25 (odds ratio: 2.543; 95% confidence interval: 1.297–4.989; p = 0.007) and Type D personality (odds ratio: 1.473; 95% confidence interval: 1.027–2.111; p = 0.035). In this short-term prospective cohort study, a significant association between periodontal disease and Type D personality was observed in Japanese university students.