PurposeThis study investigates the impact of CEO narcissism on eco-innovation. Moreover, we explore the moderating influence of CEO ancestor origins and CEO tenure on this relationship.Design/methodology/approachBased on a comprehensive dataset comprising 198 non-financial U.S. firms spanning the years 2010–2021, we apply OLS regression.FindingsOur research findings are as follows: (1) CEO narcissism negatively affects eco-innovation. (2) CEO ancestor origins play a moderating role, with this effect being attenuated for CEOs with ancestral origins from highly sustainable backgrounds. (3) CEO tenure strengthens the relationship between CEO narcissism and eco-innovation. This study sheds light on the significance of CEO personality traits in influencing eco-innovation decision-making. The results offer valuable insights for stakeholders, boards of directors and investors.Originality/valueTo the best of our knowledge, none of the studies on sustainable tools have examined the moderating effect of CEO demographics characteristics on the CEO personality traits –eco-innovation nexus, and this offers a great opportunity to make new contributions to the extant literature.