Clinical practice guidelines (CPGs) are 'systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances'. Ideally they should provide a summary of the clinical evidence about a topic, based on relevant systematic reviews, well-performed metaanalyses or individual sufficiently powered randomized trials. CPGs can help physicians and their patients to incorporate the best evidence into their individual practice but also inform further research in the field by identifying flaws and trends in the literature. Guidelines complement but should not replace clinical judgment and are not intended to define a standard of care and should thus not be used as outcome performance measures. It should, however, be recognized that in nephrology and in dialysis most of the guidelines are based on weak evidence and are mostly expert or 'consensus' based. However, there is, albeit largely indirect, evidence that adhering to CPGs is associated with improvement in dialysis care and even patient outcomes.