Purpose: The role of dialogue has recently been identified as being important in generating impact in organisations, but the purposeful use of narrative or story-based approaches to effect organisational change and service improvement is still relatively innovative. This paper documents and examines two projects in health and social care settings which aim to generate organisational development and service improvement. Design/methodology approach: The paper evaluates and compares two case studies of story based organisational development and service improvement projects in the UK. This involved developing an appropriate evaluation framework and assessing the impacts in each case using semi-structured interviews and thematic content analysis. Findings: This paper reports the diversity of impacts and outcomes that were generated by the projects. Specifically, it is argued that there is a strong indication that story-based projects best achieve their objectives when clearly linked to key organisational strategic drivers or pathways, as evidenced by robust evaluation. Practical implications: This paper recommends that researchers and practitioners, working with story-based methods, design credible and robust evaluative practices, in order to evidence how their work supports organisations to meet current sector challenges. The paper recommends a flexible evaluation framework for evaluating story-based projects in the workplace. Originality/value: This paper offers new evidence and insight into the impacts and outcomes of using story-based approaches, and a new evaluation framework for these sorts of projects.