We investigate the performance effect of former executives serving as non-executive directors. We identify and untangle the two effects of former executives: they reduce the board’s independence and monitoring capability; and with their firm-specific internal knowledge, they more effectively provide advice to the current top management team. We show that internal firm-specific factors positively moderate the former executives’ performance effect. Powerful external owners and other independent stakeholders mitigate the potential lack of independence of non-executive directors. Furthermore, complex top management team structures and a loss of executive knowledge signal an increased need for advice that such directors can satisfy.