The relative explosion in the volume and complexity of research data has made it increasingly difficult for healthcare professionals to assimilate important new findings into daily practice. This has contributed to uncertainty about the optimal management of certain conditions and, on occasion, to undesirable variation in clinical practice.Clinical practice guidelines have been proposed as a tool to help address these problems by using carefully summarised scientific data in an easy-to-understand format. The processes required to develop and implement ‘good’ guidelines are more complex than is generally recognised, however. This underlies the need for ‘guidelines for guidelines’.The article explores some of the issues surrounding the international guidelines movement and summarises key principles on which to evaluate existing clinical practice guidelines. These principles may also be used as a preliminary basis for formulating new guidelines.It is recognised that the principles set out in this document describe high standards for clinical practice guidelines. We suggest that this should not deter groups from attempting to develop guidelines, even if they do not meet all standards simultaneously. The principles embodied herein will help to define ‘good’ guidelines and ultimately lead to better standards of care for patients.