PURPOSE: The purpose of this study was to identify relationships of periodontal disease and health related quality of life (HRQoL) in pregnant women. METHODS: The participants in this study were 129 pregnant women. Data were collected using questionnaires of characteristics of the participants and subjective perception of periodontal disease and a dentist's assessment of periodontal disease. Data were analyzed using descriptive statistics, correlation, and hierarchical multiple regression. RESULTS: The physical QoL showed significant negative correlation with subjective perception of periodontal disease (r=-.21, p=.013). Mental QoL had significant negative correlations with subjective perception of periodontal disease (r=-.32, p<.001) and objective periodontal disease (r=-.34, p<.001). Hierarchical multiple regression analyses revealed that pregnant women who had a history of abortion and had higher subjective perception of periodontal disease tended to report lower levels of physical QoL. Pregnant women whose age are between 30-34 years and higher subjective perception and objective periodontal disease tended to report lower mental QoL. CONCLUSION: To improve HRQoL of pregnant women, nurses should pay attention on the status of periodontal disease. Careful assessment of oral healthy behaviors and proper intervention for oral health of pregnant women are needed to enhance HRQoL of pregnant women.