Health care often involves ethically difficult situations that may disquiet the conscience. The purpose of this study was to develop a questionnaire for identifying various perceptions of conscience within a framework based on the literature and on explorative interviews about perceptions of conscience (Perceptions of Conscience Questionnaire). The questionnaire was tested on a sample of 444 registered nurses, enrolled nurses, nurses' assistants and physicians. The data were analysed using principal component analysis to explore possible dimensions of perceptions of conscience. The results showed six dimensions, found also in theory and empirical health care studies. Conscience was perceived as authority, a warning signal, demanding sensitivity, an asset, a burden and depending on culture. We conclude that the Perceptions of Conscience Questionnaire is valid for assessing some perceptions of conscience relevant to health care providers.