Abstract— Career burnout is a painful experience for individuals and for organizations is a costly phenomenon. Plateau is a key factor for increasing this problem and mental maturity could reduce to some extent the relationship between the two variables. Hence, the aim of this study was to investigate the relationship between career plateau and burnout due to the moderating role of nurse’s psychological maturity in Arjomand and Razieh-Firoz hospitals in 2014. In this study, correlational and cross-sectional method is used. The population of this study consisted of nurses in Arjomand and Razieh-Firoz hospitals that the total number is 142 people. To determine the sample size of 100 people chosen based on Morgan table. The study used three questionnaires: plateau questionnaire validity 0.98 and reliability 0.94-questionnaire career burnout with validity 0.98 and reliability 0.93 and the questionnaire individual trust with reliability 0.94 and validity of 0.92 and mental maturity questionnaire validity 0.95 and reliability 0.88. For data analysis, the approach of partial least squares (PLS) with Smart PLS 2 software used. The results showed that there is relationship between plateau and its components with career burnout in Arjomand and Razieh-Firoz hospitals. In addition, there is not relationship between the moderating role of nurse’s psychological maturity of plateau (plateau job content) with career burnout, in Arjomand and Razieh-Firoz hospitals. However, there is an inverse relationship between the moderating role of psychological maturity at plateau hierarchical relationship with nurse’s career burnout in Arjomand and Razieh-Firoz hospitals. Given that the individual is suffering from fatigue, soon with his colleagues, and the devastating effects that the erosion of the effectiveness and performance of the individual, the individual diagnosis and prevent the spread of the organization are essential. One of the aggravating factors is plateau that should consider in the organization. If the nurses in the workplace has high psychological maturity they can enjoy some plateau hierarchical relationship and reduce burnout. Therefore, the promotion of psychological maturity and reduce the plateau at work considered.