Today, many institutions of higher education support students in conducting practice-oriented research. This research refers to a broad array of approaches geared toward practitioners' practice. The supervision of such research is of crucial importance, but little is known about its nature and characteristics. This study examined what research supervisors and postgraduate, in-service teacher students perceive are key elements of successful action research supervision. Four action research supervisors and eight postgraduate students were interviewed. Data were analysed by using theory and empirical data. Findings reveal 24 key elements of action research supervision, which refer to supervisors' (1) skills in supporting knowledge development through and about action research and creating a supportive environment for developing knowledge, (2) knowledge and expertise in supervising action research, (3) attitude in the supervision of action research and (4) the motives driving supervisors' actions in the student-supervisor relationship.