In working life, ageing and retiring staff and managers are being replaced by younger generations which come from different working life cultures. This may give rise to different management expectations. As a result, this creates a need to assess how the concept of appreciative management is implemented in health care. The aim was to develop a valid and reliable instrument to assess appreciative management. A multi-phase, mixed-method and psychometric evaluation of the Appreciative Management Scale (AMS) was conducted. A concept analysis and systematic literature review were carried out. The instrument’s development employed a two-phase Delphi study approach including essays, survey iteration rounds and expert panel evaluation. The instrument was pre-tested and tested empirically in a survey completed by staff respondents and managers. AMS 1.0 has 83 items that are categorised into Systematic Management, Equality, Appreciation of Know-How, and the Promotion of Wellbeing at Work. The instrument was found to be valid and reliable. The AMS 1.0 scale needs to be tested internationally in order to conduct evaluative surveys of appreciative management in other countries. By using the AMS 1.0 instrument to assess managers’ management practices, managers receive valuable feedback on their own management skills and also the skills of workers.