Drawing on interviews with women and men who serve on the supervisory boards of German stock-listed companies, this qualitative study examines why some female directors seek to augment gender equality in their organizations while others do not. Those who take action do so both in formal board processes and in informal settings. A sense of belonging to women as a social group and a sense of responsibility for women in the organization are key factors in explaining why some female directors (...) contribute to gender equality. In addition, the study highlights the relevance of a board culture supportive of gender equality and positive expectations by other organizational members about female directors’ role in advancing gender equality. Board chairs influence how supportive female directors perceive the organizational context to be. Where the organizational context is not seen as supportive, those who take equality-related action anyway are experienced directors. Surprisingly, the presence of other women on the board does not appear to be related to whether or not female directors take action. Examining female directors’ actions and paying close attention to both their identities and their specific organizational settings shows how the interplay between social identity and situational opportunities and constraints affects board behavior. (shrink)