Theevaluation of supervisor training has featured weak measurement and lacked a coherent framework, limiting effectiveness. A literature review was first conducted to clarify the current status of supervisor workshop evaluations, related to the promising fidelity framework. This consists of five criteria: the workshop's design, the training (competence of the trainer), the delivery of the workshop, the learning of the participants (receipt), and the clinical practice outcomes (enactment). Second, we applied this framework to the training of supervisors (n = 17) in a cognitive-behavioural therapy (CBT) approach, by analysing one trainer leading two successive supervisors’ workshops. The review of the literature indicated that there were significant psychometric and conceptual deficiencies in the current evaluation of supervisor training. The data from the case-study analysis suggest that the manual-based workshop could be delivered with high fidelity by this trainer (e.g. the CBT approach to supervision received 89% approval). The fidelity framework provided a systematic, feasible and coherent rationale for the evaluation of supervisor training. Our preliminary findings indicated that the workshop was successful. To fulfil its promise as an improved way of evaluating supervisor training, the framework should be piloted with other trainers, instruments and workshops, using controlled designs.