AbstractPrior research demonstrated that narcissism fosters the attainment of higher managerial ranks in organizations. However, it is not known whether climbing the corporate ladder also fosters the development of narcissism over time. Whereas prior work consistently adopted a unidirectional perspective on narcissism and career attainment, this study presents and tests a bidirectional perspective, incorporating long-term development in narcissism in relation to and in response to long-term upward mobility. To this end, a cohort of highly educated professionals was assessed three times over a 22-year time frame. Extended latent difference score modeling showed that, over the entire interval, within-person changes in narcissism were positively related to within-person changes in upward mobility.