This paper presents the proposition that a variety of differing hierarchies exist in an action learning set at any one time, and each hierarchy has the potential to affect an individual's behaviour within the set. An interpretivist philosophy underpins the research framework adopted in this paper. Data were captured by means of 11 in-depth interviews that formed part of wider research into set members' perceptions of what makes an effective action learning set. The interviewees were all former students of the researcher and her colleagues. The research draws upon grounded theory as a dominant research paradigm and uses thematic analysis to interpret the research findings. The findings of the research serve to simply illustrate that there is the potential for a variety of differing hierarchies to exist in an action learning set at any one time. Some of the hierarchies may exist for the full duration of the set; others are somewhat ephemeral. The findings from this research also present themselves as points of consideration for academics and practioners who have used or are about to use action learning as a learning vehicle.