The use of patient diaries in critical care in the UK is increasing, but there is little evidence-based research available to support this. The National Institute for Health and Clinical Excellence (NICE) has recommended that services should be developed to meet the psychological care needs of patients following critical illness. One response to this has been the introduction of patient diaries. To gain insight into the use of patient diaries in critical care, a literature review was conducted. This article provides an overview of the literature and suggests how it can inform clinical practice in relation to diary use in critical care and beyond.