Objectives : This study was conducted to investigate the levels of psychosocial stress, job stress and their related factors among medical doctors practicing at local clinics. Methods : A survey using a self administered questionnaire was administered to 1,456 doctors practicing at private clinics via post for 2 months (2006. 1 - 2006. 3). Psychosocial stress, job stress, demographic factors, job related factors and health related behaviors were investigated. Among the eligible study population, the respondents were 428 doctors (29.4%). Results : The average scores of psychosocial stress and job stress were 2.19 and 3.13, respectively. The levels of psychosocial stress and job stress were statistically lower in older respondents, those who worked shorter or who were more satisfied with their job, and those with higher socioeconomic status. The level of psychosocial stress was related with smoking status, drinking status and exercise. The level of job stress was related with smoking status and exercise. In multiple linear regression analysis using psychosocial stress as a dependent variable, age, working hours per day, job satisfaction and perception on socioeconomic status were significant independent variables. In analysis using job stress as a dependent variable, age, working hours per day and job satisfaction were significant independent variables. Conclusions : Stress affects the doctor-patient relationship, productivity and overall health level of people. Therefore, it is important to manage and relieve the stress of doctors. It is suggested that more advanced studies on stress level and related factors and ways to improve the stress and health related behaviors of medical doctors should be conducted.