AbstractThough grandiose narcissism has predominantly been studied in structural terms—focused on individuals' general tendencies to be more or less narcissistic—we tested whether it also has a meaningful process or state component. Using a daily diary study methodology and multilevel modeling (N = 178 undergraduates, 146 female; Mage = 18.86, SD = 2.21), we examine whether there is significant variability in daily state narcissism and whether this variability relates systematically to other psychological states (i.e., self‐esteem, stress) and daily events. We assessed state narcissism and daily experiences over a 10‐day period. We observed significant within‐person variability in daily narcissism. Notably, this variability was not simply random error, as it related systematically to other psychological states and daily events. Specifically, state narcissism was higher when people experienced more positive agentic outcomes (e.g., having power over someone) or more positive communal outcomes (e.g., helping someone with a problem). State narcissism was lower on days people experienced greater felt stress. These relations held when state self‐esteem, gender, and trait narcissism were controlled. These findings suggest that grandiose narcissism has a meaningful process or state component.