The aim of this research is to examine what impact female institutional directors on boards have on corporate performance. Previous research shows that institutional female directors cannot be considered as a homogeneous group since they represent investors who may or may not maintain business relations with the companies on whose corporate boards they sit. Thus, it is not only the effect of female institutional directors as a whole on firm value that has been analysed, but also the impact of pressureresistant female directors, who represent institutional investors (investment, pension and mutual funds) that only invest in the company, and do not maintain a business relation with the firm. We hypothesise that there is a nonlinear association, specifically quadratic, between institutional and pressureresistant female directors on boards and corporate performance. Our results report that female institutional directors on boards enhance corporate performance, but when they reach a certain threshold on boards (11.72%), firm value decreases. In line with female institutional directors, pressureresistant female directors on boards also increase firm value, but only up to a certain figure (12.71% on boards), above which they have a negative impact on firm performance. These findings are consistent with an invertedU shape relationship between female institutional directors and pressureresistant female directors and firm performance.