The purpose of this study was to examine the periodontal care of dental clinic patients. The subjects in this study were 213 patients who visited four different dental clinics in the region of Geoje. After a survey was conducted, the following findings were given: 1. In regard to the prevention of periodontal diseases, 52.1 percent of the patients investigated received treatment at a dental clinic when their gums were swollen or bleeding, and the way they responded to their swollen or bleeding gums was significantly different according to age, occupation(p<.01) and academic credential(p<.001). 31.0 percent got their teeth scaled to take care of their gums, and how to take care of the gums differed significantly with age, occupation, academic background(p<.001) and monthly income(p<.01). As to yearly preventive treatment frequency for periodontal diseases, 22.5 percent received treatment to prevent any possible periodontal diseases once a year, and age, educational background(p<.01) and occupation(p<.05) made a significant difference to that. By occupation, the company employees received more preventive treatment. As many as 66.7 percent intended to receive education on the prevention of periodontal diseases if there would be any chance, and gender and age(p<.001) made a significant differences to that. 2. As for oral health care habits, 52.1 percent brushed their teeth in a mixed way, up and down and right and left, and the women did that up and down more than the men. Those who were in their 30s did toothbrushing in the mixed way the most, and gender(p<.05), age(p<.05) and academic credential(p<.001) made a significant difference to that. Concerning daily mean toothbrushing frequency, 43.7 percent did that three times a day, and the women who did that three times outnumbered the men who did. The daily mean toothbrushing frequency varied significantly with gender(p<.01). By occupation and education, the professionals and better educated patients were significantly different from the others in that regard(p<.01). As to the use of an interdental brush, 57.3 percent had ever used it, and those who were better educated, who had a larger monthly income(p<01) and who were professionals(p<.001) were significantly different from their counterparts in that aspect. As to scaling experience, as many as 68.5 percent had ever had their teeth scaled, and those who were in their 30s had done that the most. Age made a significant difference to that(p<.01), and the professionals, larger income earners and better educated patients were significantly different from their counterparts in that regard(p<.001). The findings of the study justified the necessity and importance of periodontal care, and the prevention of periodontal diseases, regular dental checkup and the development of oral health education programs were required.