Appointing an external (i.e. a non-family member) CEO is argued to be an important decision for family firms (e.g., Dyer, 1986; Miller et al., forthcoming). Family firms recruiting an external CEO have been found to outperform those that appoint a family member as the CEO (Bennedsen et al., 2007). While there is a large body of literature focusing on the appointment of outside management in family firms, there is a lack of studies investigating factors influencing the likelihood for an external CEO to remain in the position, i.e. the length of their tenure. Building on the theory of embeddedness and homophily, we investigate the impact of CEO characteristics, board diversity and CEO dissimilarity on the longevity of external CEOs.