Evaluation of group work supervision literature suggests that description of expert group work supervisors' experiences could be useful for expanding existing group work supervision practices and models. This study provided a systematic exploration of the experiences of expert group work supervisors during the supervision process. Results indicate that group work supervisors experience a process of conceptualization and critical reflection that guides their supervisory actions. This process occurs within the contexts of beliefs about group work, supervision, and knowledge about self, supervisee(s), and supervisees' groups. The article addresses limitations of the study, provides implications for training of supervisors, supervision, and research. (Contains 1 figure.)