OBJECTIVE Older adults often suffer from multimorbidity, which results in hospitalisations. These are often associated with poor health outcomes such as functional dependence and mortality. The aim of this review was to summarise the current literature on the capacities of morbidity measures in predicting activities of daily living (ADL) and instrumental activities of daily living (IADL) amongst inpatients. METHODS A systematic literature search was performed using four databases: Medline, Cochrane, Embase, and Cinahl Central from inception to 6th March 2019. Keywords included comorbidity, multimorbidity, ADL, and iADL, along with specific morbidity measures. Articles reporting on morbidity measures predicting ADL and IADL decline amongst inpatients aged 65 years or above were included. RESULTS Out of 7334 unique articles, 12 articles were included reporting on 7826 inpatients (mean age 77.6 years, 52.7% females). Out of five morbidity measures, the Charlson Comorbidity Index was most often reported. Overall, morbidity measures were poorly associated with ADL and IADL decline amongst older inpatients. CONCLUSIONS Morbidity measures are poor predictors for ADL or IADL decline amongst older inpatients and follow-up duration does not alter the performance of morbidity measures.