Objectives : The present study was designed to investigate the possible relationship between job stress and mental health in a group of hospital employees of Shiraz University of Medical Sciences. Method: Three hundred and ninety-seven employees (150 administrative and 247 medical staff) were selected randomly through stratified random sampling. They were requested to answer the General Health Questionnaire (GHQ) and Pickle Paykel Life Inventory. Results: The findings revealed significant correlation between job stress and mental health. The medical staff showed significantly lower level of mental health when compared with office workers. More desirable level of mental health in males was observed in contrast to the female participants. Conclusion: The findings of the present study signify the importance of organization care to the mental health of the employees particularly those directly involved with patients and female personnel in general .