This study explored whether accountability influences the relationship between power and leader self-serving behavior. Across three studies, using both experimental manipulations and individual difference measures, we found that accountability mitigated the effects of power on leader self-serving behavior. Specifically, we found that powerful accountable leaders acted less self-servingly than their non-accountable counterparts. Moreover, as expected, low power leaders' behaviors were not affected as strongly by the explicit presence of accountability constraints. Overall, these results suggest that holding powerful leaders accountable for their actions could serve as a powerful tool to prevent potential self-serving actions on their part.