OBJECTIVE The aim of the study reported here was to evaluate the role of intuition, to examine nurses' understanding of intuition and their perceptions of their use of intuition, and to assess the impact of intuition on nursing practice. BACKGROUND When we read the dictionary definition of intuition, we have a sense of the meaning but there is also a sense of something still not quite defined. Yet we instinctively know what intuition is. That is, of course, an example of intuition in itself: an understanding of the concept based on our feelings, knowledge and experience. Intuition is a concept neither clearly articulated nor adequately theorized in nursing. There is evidence to suggest that practising nurses use intuition and that its use can change outcomes for patients. Because of its influence on patient well being, it needs to be recognized as an important tool in the practice of nursing. The very nature of intuition determines that there will be little agreement on a precise definition and little empirical evidence to support its existence or worth. Neither of these issues detracts from the fact that intuition is an important part of nursing. METHODS Grounded theory was used as the overarching theoretical and methodological framework for this study. Using focus group interviews and the Delphi survey technique, data were collected from 262 Registered Nurses who volunteered to take part in the study. RESULTS The theory that emerged from this study provides nurses with a way of articulating their understanding of intuition and their perceptions of its use in nursing practice. CONCLUSIONS Intuition is not some mystical power that appears from nowhere, with no rational explanation or basis. The findings from this study show that it is a product of the synergy that occurs as a result of the interaction of a number of factors.