This research explores brain-behavior relationships in prosocial, effective leadership by introducing executive function (higher-order brain function) as an individual difference. One hundred and five mid-level and senior managers were assessed on scientifically-valid neuropsychological tests that capture important dimensions of executive function. Two dimensions of executive function, control (inhibition of pre-potent response, flexible thinking) and decision-making, interacted to predict transformational leadership. This effect was found controlling for the extant antecedents of extraversion and general mental ability. Specifically, transformational leadership was associated with (1) high inhibition of pre-potent response in the presence of low-risk decision-making, and (2) either mental flexibility or low-risk decision-making, interchangeably. This suggests that the relationship between various executive function constructs and leadership is complex, and strengths in some cognitive capacities can substitute for limitations in others. Implications of the role of these interactions in facilitating transformational leadership are discussed.