We describe a small hypothesis-generating study of the use of a measure of complexity of mind in coaching contexts. The aims of the pilot study were threefold: (a) to explore participants’ coaches’ and interviewers’ insights and reactions to the use of a developmental theory in coaching; (b) to develop and explore a process for using the Subject-Object Interview (SOI) inside or outside existing coaching relationships; and (c) to provide a preliminary evaluation of the usefulness and/or potential limitations of the SOI for coaching contexts. All 15 participants in this qualitative study enjoyed the process and most reported significant or profound insights arising from the process that were potentially useful for their own development. The process revealed some of the growing edges of the clients’ insights into their own way of being their relationships and their work. Importantly participants reported that the SOI and associated discussions allowed them to identify key developmental issues more quickly than other approaches they had experienced. While the time and high skill levels associated with conducting an SOI and feedback discussion may preclude its use in many coaching contexts there are implications that arise from this work for coaches interested in working in developmentally-informed ways.