BackgroundUse of certain medications during an acute illness may put patients at an increased risk of acute kidney injury (AKI). Patients with chronic kidney disease (CKD) are at higher risk of developing superimposed AKI. The aim of this scoping review is to collate and characterise existing evidence on sick day management considerations and practices during acute illness in people with CKD.MethodsWe searched Embase, CINAHL, MEDLINE, International Pharmaceutical Abstract, Scopus, Google Scholar and grey literature sources. We followed the methodological framework for scoping reviews, while information was extracted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. Findings are presented thematically.ResultsTen studies and seven guidelines met the inclusion criteria. Studies were targeted at patients, general practitioners, pharmacists, and nurses. The major themes identified included development and feasibility testing of a sick day management protocol, current practice of temporary medication discontinuation, and outcomes. Most guidelines provided recommendations for sick day management largely based on expert consensus. A digital intervention was deemed highly acceptable and easy to use, whereas patient handouts were more effective when provided along with dialogue with a health professional. While there is little evidence on the impact of sick day protocols on outcomes, a single randomised trial reported no significant association between sick day protocols and change in kidney function, AKI incidents or risk of hospitalisation.ConclusionThe nascent literature on sick day management in patients with CKD revealed the limited available evidence to provide guidance on implementation and on outcomes. Future research needs to clarify sick day recommendations and assess their impact on clinical outcomes including prevention of superimposed AKI or hospitalisations, as well as to address barriers to implementation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40620-022-01497-5.