There is a great deal of interest in the United Kingdom in clinical guidelines as a means of assisting practitioner and patient decision making about care options and in improving the quality of the care provided. Confusion remains, however, over what is meant by a clinical guideline and how it differs from and relates to protocols and standards. This paper was written under the auspices of the Royal College of Nursing Steering Group for the college's work on clinical guidelines, with the aim of clarifying some of the terminology used in the field and introducing ways in which clinical guidelines might be used by practitioners and patients to readers. At the moment just how effective the use of clinical guidelines can be on care is poorly established. What is known, however, is that crucial to their success are the strategies and methods used for their implementation. Such strategies and methods raise questions about how a sense of ownership can be engendered in those using the clinical guidelines and how they may be best operationalized. These questions are considered in this paper.