The presence of women on boards of directors has become a high profile issue in recent years. Several studies, based largely on data from countries with Anglo-Saxon corporate governance systems, have investigated the influence of female board appointments on firm performance. This study focuses on the impact of female directors in Spain, where debate about this topic has been intense for two reasons: the recommendation in 2006 by Spain’s Unified Good Governance Code of positive discrimination in favour of female board appointments and the passing in 2007 of a Gender Equality Act by the Spanish parliament. Our paper analyses the short and long term effect of the appointment of female directors prior to these events. We use an event study to analyze the short term stock market reaction to the appointment of female directors and a multiple regression approach, using the system GMM estimation procedure, to assess the long term influence on firm value of female boardroom appointments. We find that the stock market reacts positively in the short term to the announcement of female board appointments, suggesting that investors on average believe that female directors add value. This belief appears to be confirmed by our regression results which show that female board appointments are positively associated with firm value over a sustained period. These results suggest that the legislative changes in Spain make economic sense as well as advancing the cause of women in Spanish boardrooms.