Purpose - Drawing on the social exchange theory and the stressor-strain framework, the purpose of this paper is to examine the relationship between leaders' narcissism and employees' organizational cynicism. Specifically, the authors take a relational approach by introducing employees' psychological strain as the mediator. The moderating role of psychological capital in the relationship between leaders' narcissism and employees' cynicism is also considered. Design/methodology/approach - The data of this study encompass 1,215 certified nurses from 15 university hospitals in Turkey. Hierarchical multiple regression analysis was conducted to test the proposed model. Findings - The statistical results of this study supported the positive effect of leaders' narcissism on employees' cynicism as well as the mediating effect of employees' psychological strain. Moreover, when the level of psychological capital is high, the relationship between leaders' narcissism and organizational cynicism is weak, whereas the effect is strong when the level of psychological capital is low. Practical implications - The findings of this study suggest that managers in the healthcare industry should be sensitive in treating their subordinates, as it will lead to positive interpersonal relationship, which, in turn, will reduce employee cynicism. Moreover, managers should pay more attention to the buffering role of psychological capital for those employees with high psychological strain and showing organizational cynicism. Originality/value - As the healthcare sector continues to go through a transformational change, it is important to identify organizational factors that affect employee attitudes. There is limited empirical evidence about the determinants of cynicism, particularly in the healthcare sector environment. This study contributes to the literature on organizational cynicism by revealing the relational mechanism between leaders' narcissism and employee cynicism. The paper also offers a practical assistance to employees in the healthcare management and their leaders interested in building trust, increasing leader-employee relationship and reducing organizational cynicism.