The purpose of this study is to explore the correlation between work-family conflict (WFC) and job stress among government public service employees, along with the moderating role of psychological capital (PsyCap) in this correlation. Data were collected from 204 respondents. Respondents working in the government public service in Daerah Istimewa Yogyakarta spread in 5 district office. The result showed there are WFC and PsyCap able to predict the job stress levels of employees. In addition, PsyCap can also be moderated the correlation between WFC and job stress. The result indicates that if there is WFC experienced by employees with low PsyCap it can increased the job stress. The results of this research can be used to help employees develop their potentials in preparing to cope with problems that appeared because of the demands in the workplace and family responsibilities.