This study investigates how CEO narcissism interacts with family CEO identity to shape firms’ dynamic cash management behavior, specifically the speed of adjustment toward target cash holdings. Using a sample of non-financial firms listed on the Taiwan Stock Exchange and the Taipei Exchange, we find that family-control firms led by narcissistic family CEOs exhibit a significantly faster cash adjustment speed compared to those led by narcissistic non-family CEOs. Within family firms, the speed of cash adjustment is higher when the CEO is a narcissistic founder than when the CEO is a narcissistic heir. These heterogeneous effects are more pronounced in firms with greater information asymmetry, suggesting that narcissism flourishes in environments with weaker monitoring. Overall, the findings highlight the importance of CEO psychological trait and CEO identity in understanding dynamic cash adjustment behavior.