ObjectiveTo systematically review the efficacy of ICU diaries on psychological outcomes, cognition and health-related quality of life in both patients and their relatives. MethodsThe PubMed, Embase, Web of Science, Cochrane Library, PsycINFO, CNKI, WanFang Data and VIP database were electronically searched to collect trails related to the objective from inception to August 2023. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.3 software. ResultsA total of 17 studies involving 2 093 patients and 786 relatives were included. The results of meta-analysis showed that compared with the control group, ICU diaries could improve patients’ post-traumatic stress disorder (PTSD) (RR=0.64, 95%CI 0.50 to 0.83, P<0.01), depression (RR=0.65, 95%CI 0.48 to 0.89, P<0.01) and quality of life (MD=7.78, 95%CI 4.37 to 11.18, P<0.01) significantly. However, there were no significant differences in patients’ anxiety, memory and relatives’ psychological outcomes. ConclusionCurrent evidence shows that the use of ICU diaries can reduce the incidence rate of patients’ PTSD, depression and improve their quality of life, but other effects are unclear. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.