Introduction: Mental health is one of the social needs and disorders such as depression and anxiety are discussed as the most common diseases, today. Nurses who working the night shift more than other professions in other scheduling are vulnerable to psychological stress. Aim: This study was done for assessing the relationship of the night shift work with nurses' depression and anxiety in hospitals of Chalous city in 2014. Methods and Materials: It was a descriptive-correlation study that (140) nurses who worked in night shift selected randomly according to Krejcie and Morgan's. Beck depression-II and Beck anxiety inventories were used for collection data. In past, their reliability measured in Iran, in this study &alpha Chronbach were (0.93 and 0.92) respectively. Data analyses by Pearson test, MANOVA and independent t-test with SPSS17. Results: The findings indicated that there was a positive and significant relationship between the night shift work and nurses' depression and anxiety (P &le .05). In other words, the night shift work has correlated with nurses' depression and anxiety. Also, gender and education has no relationship with nurses' depression and anxiety of night shift work (P > .05). There was not a significant difference between nurses' depression and anxiety of night shift work based on their marital status (P > .05). Conclusion: It would be suggested that nurse managers plan properly in scheduling and decreased night shift in regarding to improve nurses' mental health.