As the coaching process is confidential, little is known about the dynamics of how coaching themes evolve from the initial coaching objectives in actual coaching relationships. This study aims to explore the content of coaching engagements in organisational settings. By ‘content’ we mean what is demonstrably discussed in coaching: goals as agreed with the organisation from the initiation of coaching, the themes of the coaching conversations and how these themes evolve over the coaching engagement. By organisational coaching we mean the coaching practice that involves a third-party sponsor. This study is designed as large-scale mixed method research which aims to classify and quantify coaching themes on the basis of primary data about what organisational coaches report as having addressed in their coaching engagements. The key proposition of this study is that content themes shift during the coaching engagements in organisational coaching. A qualitative pilot study has already been completed by Bachkirova & Lawton-Smith in 2016 as part of an internal research project at Oxford Brookes University. It provides an initial confirmation of this proposition and will serve to inform the design of data collection methods and a framework of initial content categories. Knowledge about the content of real coaching engagements will allow the development of a grounded classification of coaching themes and therefore would contribute to the debates about what is an essential aspect of coaching (i.e. content). An opportunity for specialisations in education and CPD of coaches would be an important contribution to practice.