Studying turnover in humanitarian organisations a" i.e., the question who stays and who goes a" can provide insight in patterns of inclusion and exclusion in humanitarian organisations, and the role of formal hierarchy therein. This chapter investigates the impact of one particular form of formal hierarchy a" the human resource management practice of role clarity a" on turnover. Aid workers face task requirements that are inherently complex and uncertain, and insights from the for-profit sector imply that role clarity is an effective way to reduce uncertainty and turnover intentions. The authors argue, however, that in the highly complex task environments of humanitarian work, role clarity can only reduce turnover if social relations between co-workers a" an element of feeling included in the organisation a" are of high quality. They analyse data generated by a survey amongst 146 employees working for Mã©decins Sans Frontiãres (MSF), one of the largest humanitarian agencies in the field. Results reveal that the quality of social relations reduces turnover intentions, whereas role clarity has no direct effect on turnover intentions. Role clarity only reduces turnover intentions if social relations with coworkers are of high quality. This study thus provides evidence that this particular form of hierarchy only affects turnover positively if this goes together with feeling included in the group of colleagues.