Gender diversity as a corporate governance mechanism is high on the agenda for regulators, firms, and researchers. Particularly, gender board composition has received a great deal of attention in recent years. The theoretical foundations of the benefits associated with the inclusion of female directors on boards, how to measure gender diversity in the boardroom, and its real impact on board decisions and firm strategies remain hotly debated. Drawing on empirical data, this book summarises the current situation regarding gender board diversity and provides a concise overview of the most important concerns about this topic.