Objectives: This study furthers the currents understanding of mental health status and stress level among Seoul citizens and to identify differences according to socio-demographic variables for developing mental health programs. Methods: The study subjects using cluster-stratified sampling method were 1234 adults over 19 years old from 17 dong, S-Ku in Seoul City. A cross-sectional study with face-to-face interview was used to collect data. A questionnaire measuring socio-demographic variables, Symptom Checklist-90-Revised (SCL-90-R) and psychosocial wellbeing index-short form (PWI-SF) was utilized. Results: Three findings in this study were discussed: (1) The rate of clinical mental health was low in contrary to that of border group which was high and the rate of high risk group of stress was 68.1% (men 67.0%, women 69.0%); (2) The mental health and the stress level was significantly higher among female, elderly, lower education level, divorced, and lower family income; and (3) In Pearson correlation analysis, stress were correlated to all 9 symptoms of SCL-R. Conclusion: The findings suggest that the future intervention of Mental Health programs should be carefully designed and tailored by socio-demographic variables.