In a previous study (Wilde et al. 1993), we developed a model of quality of care from a patient perspective using a grounded theory approach. The aim of the present study was to derive an instrument from this model. A questionnaire, Quality from Patients' Perspective (QPP), was developed which consisted of 56 items. Each item was evaluated in two ways by the respondent; assessment of perceived reality and evaluation of subjective importance (Likert scales). A personal quality of care index was computed on the basis of the relationship between these two scores. The QPP was tested on two samples, patients with infectious diseases (n = 147, mean age: 60 years) and nursing students (n = 103, mean age: 27 years). Patient's scores were factor analysed (principal factoring with oblique rotation) and 17 factors were extracted. Subgroups of patients were compared and correlations were computed between factor scores and self-rated health and well-being. Students also responded to a short form of the QPP (41 items) and personality scales. Correlations between these sets of variables were computed. The QPP was discussed in relation to existing scales.