Objectives: Huber et al. introduced a new concept ‘positive health’, defined as ‘the ability to adapt and self-manage in the face of social, physical and emotional challenges’ and suggested a conceptual model comprising six domains covering 32 aspects. Our aim was to generate items and pilot test an outcome measurement instrument for measuring ‘positive health’ in Dutch adult citizens. Study design: A mixed-method study: a literature search, a qualitative study with interviews and a quantitative ranking study for the development phase, to be followed by a content validity study for the validation phase. Methods: We developed items based on the concept elicitation study of Huber et al. A ranking study with end users, Dutch citizens and members of an Expert Group was performed for item reduction. Content validity of the prefinal questionnaire was evaluated. Results: A prefinal 46-item questionnaire was developed. The results of the content validity study, however, showed major concerns with regard to relevance, comprehensiveness and comprehensibility of the questionnaire. Conclusions: Because of major concerns regarding the conceptual model of ‘positive health’, it was not possible to develop a valid questionnaire to measure ‘positive health’. Future research should focus on the refinement of the conceptualization of ‘positive health’ before an adequate measurement instrument could be developed that can be used for outcome measurement purposes.