ABSTRACT We examine the association between CEO narcissism and the likelihood of engaging in related party transactions (RPTs) and its influence on the value implications of these transactions. Furthermore, we investigate the effect of board monitoring on the relationship between CEO narcissism and the value effects of RPTs. We find that CEO narcissism is positively associated with the propensity for RPT engagements. We also highlight the detrimental effect of RPTs conducted by narcissistic CEOs by documenting that RPT engagements have a negative (positive) effect on firm performance at high (low) levels of CEO narcissism. In addition, we show that strong board monitoring moderates the negative influence of CEO narcissism on the value implications of RPTs. Overall, we find evidence of the opportunistic behavior of narcissistic CEOs engaging in value‐reducing RPTs. We also underscore the significance of board monitoring in mitigating the adverse effects of CEO narcissism on the RPT‐firm performance association.