--- - |2+ Abstract Objective Using the narcissistic admiration and rivalry concept as a guiding framework, the current research examines how ingroup affiliation and devaluation are connected to the self‐enhancing and self‐threatening properties of ingroups for narcissists. Method Participants (N = 374) completed a group decision‐making task and received feedback that factorially manipulated both individual and group performance. Across the four combinations of performance feedback, we examined the conditional effects of narcissistic admiration and rivalry on social identity, perceptions of group member ability, desire to abandon the group, and desire to expel group members. Results Narcissistic admiration predicted higher levels of social identity in response to ingroup success, regardless of individual performance. In contrast, narcissistic rivalry predicted more negative views of group ability, as well as higher desire to abandon the group and expel group members in response to individual success combined with ingroup failure. Conclusion The results document and provide insight into narcissists’ fickle attachment to ingroups. They provide evidence of the utility of the narcissistic admiration and rivalry concept in group contexts. Our findings suggest that narcissistic admiration is linked to self‐enhancing group affiliation, whereas narcissistic rivalry is related to self‐protective group distancing and devaluation. This article is protected by copyright. All rights reserved. - Journal of Personality, Volume 0, Issue ja, -Not available-.