Purpose: This research paper presents an innovative evaluation methodology which was developed as part of a doctoral research study in a voluntary sector youth organisation in England. Design/methodology/approach: The transformative methodology synthesises aspects of appreciative inquiry, participatory evaluation and transformative learning and engages the whole organisation in evaluating impact. Using an interpretive paradigm, data were collected from youth workers via semi-structured interviews prior and post implementation of the transformative evaluation methodology. Findings: Drawing on thematic analysis of the youth workers' experiences, it is argued that the illuminative and transformative nature of the methodology enabled the learning and development functions of evaluation to be realised. Further, it is argued that this form of evaluation not only supports the collection of evidence to demonstrate impact externally, but that the process itself has the potential to enhance practice, improve outcomes "in the moment" and promotes organisational learning. Research limitations/implications: The research findings are limited by the small-scale nature of the project. Further research is needed to investigate the supporting and enabling factors that underpin participatory practices in organisation evaluation; and in particular to investigate the experience of the managers and trustees as these were not the focus of this research. Originality/value: This article makes a significant contribution to knowledge in regard to the design and use of participatory evaluation. It evidences the benefits in relation to generating practice improvements and for practitioners themselves in terms of countering the negatives effects of performativity. Transformative evaluation offers an innovative structure and process through which organisational learning can be realised.