In this thesis we show how and why non-family managers are excluded in family firms. Additionally, we depict the implications of exclusion on an individual as well as a business level. The literature framework that consists of literature from family business and organizational as well as socio-psychological studies lays the foundation for our qualitative empirical research. A method triangulation of semi-structured interviews and vignettes, based on empirical material from seven cases, is applied to understand the exclusion of non-family managers. Our findings suggest that exclusion is prevailing in family firms. Hereby, family members as well as non-family managers can be the ones excluding. We identified six main categories why exclusion of non-family managers happens. Exclusion can be based on the family’s values and norms, exclusive knowledge of a family member, the need of quick decision making, the need of secrecy, the manager’s professional values and norms, as well as the manager’s personal values and norms. Further, exclusion can take place in formal and informal selective arenas, through formal and informal breach of agreements, through structural and cultural hindrances, as well as through differences between enacted and espoused values. Moreover, we reveal several implications exclusion has on an individual and on a business level. The findings contribute to the theoretical and managerial understanding of exclusion in family firms. Thus, increasing the awareness of its existence in family firms. Additionally, we contribute to current research about exclusion in family firms by providing more insights into the complex phenomenon. This thesis is of interest to any individual in a leading position in family firms, as well as academics in the research field of family businesses.