The purpose of this study was to investigate dietary behaviors and health-related lifestyles of adult visitors at a public health center in Gyeonggi urban area. A survey using questionnaire was conducted with 949 visitors at Seongnam public health centers from June to August, 2012. The data from 905 respondents were analyzed by gender, consisting of 322 males and 583 females, and age group, consisting of 243 low-age group (LA), 312 middle-age group (MA), 350 high-age group (HA), aged 20 to 30 years, 31 to 50 years, and 51 to 69 years, respectively. Average Body Mass Index was 23.0, which increased with age, and education level was high in LA. 59.0 percent of the subjects had various diseases, and the incidence of hypertension was the highest, followed by allergy, hyperlipidemia, diabetes mellitus, joint rheumatism. Incidence rates of chronic disease increased with age, which were lower than those from 2011 Korea National Health and Nutrition Examination Survey (KNHANES). Weekly drinking frequency rate and smoking rate decreased with age, and exercise performing rate was high at male and HA, which showed the same tendency as KNHANES. Female and HA showed more healthy dietary behaviors such as restricting salt, sugar, oily foods, foods containing food additives, calorie, caring for balanced diet, and referring to nutrition label. Subjects chose stress as the first factor, followed by diet, exercise, etc., among 13 suggested factors which strongly influence on human's life-span. In general, public health center visitors, especially female and HA, showed better dietary behaviors and health-related lifestyles compared with KNHANES.