Organizational flexibility is very important for firms to better cope with the turbulent external environment, adapt to technological changes and innovate better. Following the literature on the bright and dark sides of narcissism, we develop a moderated mediation model to examine the impact of Chief Executive Officer (CEO) narcissism on organizational flexibility. Using a sample of 116 firms in mainland China, we found support for the moderated mediating process. When narcissistic CEOs strongly identify with their organization, the mediating effect is positive on organizational flexibility through the TMT collaborative conflict culture. When narcissistic CEOs weakly identify with their organization, the mediating effect is negative. Our research identified both a mediating mechanism (i.e., the TMT collaborative conflict culture) and a boundary condition (i.e., CEO organizational identification) for the relationship between CEO narcissism and organizational flexibility. We corroborate earlier research on the crucial role of CEO organizational identification in suppressing the detrimental effects of CEO narcissism and enlarging its beneficial influence. We also focus on the collaborative conflict culture as a more practice-oriented TMT process.