This paper investigates the influence of managerial ability on the relationship between lean implementation and hospital performance. The analysis, based on a longitudinal dataset of U.S. hospitals from 2002 to 2018, lends support that lean implementation improves hospital performance and that such relationship is stronger in the presence of higher managerial ability. This paper uncovers a context-dependent mechanism underlying the relationship between lean implementation and hospital performance. Overall, this study paints a broader picture of the moderating role of managerial ability in driving hospital success.