Abstract : Periodontal diseases are common oral health problems worldwide and affect up to 50% of the population globally. The bidirectional relationship of periodontal diseases with various systemic diseases has been reported in several studies. The successful prevention and management of periodontal diseases depend on the knowledge and attitude of medical practitioners towards the oral health. Hence, this study was undertaken to assess the knowledge, attitude and practice of medical practitioners of Kuala Muda district towards the relationship between periodontal health and systemic diseases. Ninety-five medical doctors from various specialties of medicine were included in this cross-sectional study. A self-administered questionnaire was used to evaluate the knowledge, attitude and practice of medical doctors. Though the mean periodontal knowledge scores of specialists (10.37±1.617) were slightly higher than the mean scores of general practitioners (9.83±1.564), the difference was not statistically significant (p= 0.105) at the 0.05 significance level. There was a statistically significant (p = 0.037) negative correlation (r = -0.215) noted between the years of practice/experience of medical doctors and their mean periodontal knowledge scores. The study demonstrates that medical doctors had fair knowledge about the periodontal diseases and their relationship with the systemic diseases. However, the practice and attitude of medical doctors towards the screening/referral of patients for oral and periodontal health checkup needs to be improved.