Audit involves the recording of a process to allow evaluation against best practice leading to improvement. There is an increasing necessity for clinical audit of low vision rehabilitation services, which must be based on validated, standardised techniques. Although there are several research papers examining measures of visual function used in low vision clinics, few attempt a clinical audit cycle. Therefore this article examines the process of clinical audit of adult low vision rehabilitation services and current knowledge of evidence-based best practice. It was found that, although much research has been conducted to validate the measurement of some areas of visual function, such as visual acuity and quality of life, there is little standardisation or validation of other measures, such as visual field quantification. In conclusion, adult low vision rehabilitation services are appropriate for clinical audit under the framework of ISO 9001:2000, although some areas are identified in which evidence for best practice is yet to be established. (Wolffsohn and Karas).