D.Comm. (Leadership Performance and Change) / The purpose of this thesis is to develop a theory, which is based on the career transition phenomenon as experienced by transitioning individuals. Specific focus is given to professionals who transition either to a new profession where a new South African Qualifications Authority (SAQA) qualification is required, or to a wholly unrelated non-professional job where no new qualifications are required. This thesis also provides a theoretical overview of the movement from old career concepts to new career concepts and its related influence on both individuals, as well as the organization, as this is the environment in which career transition take place. An interpretive qualitative approach with a specific grounded theory strategy was employed. Data and information was collected by way of memoirs, interviews and literature. The data came from a total of eight participants who each submitted a personal account of their career transitions as they experienced it in the form of a memoir. Additional data was collected via structured interviews, where participants were requested to provide their inputs and comments. These interviews were also a form of member checking, as the questions were developed based on the initial analysis of their memoirs. Information was also collected from literature, where any and all related career transition concepts were explored, and included in the final analysis. The specific application of grounded theory that was followed to analyse the data was Straussarian. This analysis process entails three steps. Firstly, the researcher applied open coding, followed by axial coding, and, lastly selective coding. Each new participant who was analysed was chosen by following the theoretical sampling technique. The qualitative data analysis software programme called ATLAS was utilized to store all data that was collected, including the developed codes and theoretical memos. Mind maps were developed as the analysis progressed and assisted in the development of the final story on career transitions. Data analysis ended when theoretical saturation was obtained.