AIMS: To identify and report results from studies of anxiety and depression, as measured by The Hospital Anxiety and Depression Scale (HADS) in patients ≥ 80 years admitted to hospital settings, and to inform nurses, researchers and educators in nursing about these findings. DESIGN: Systematic review. DATA SOURCES: MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane, Epistemonikos, Scopus and Web of Science Core Collection of studies published until October 2023. METHODS: A search strategy was developed with a university librarian. Four independent reviewers screened titles and abstracts based on predefined inclusion criteria. Data were systematically extracted, descriptively analysed, and Critical Appraisal Skills Programme checklists were used to assess studies. RESULTS: Out of 7076 identified studies, three met the eligibility criteria. Data from 420 participants aged ≥ 80 years were analysed, revealing anxiety prevalence rates between 6% and 18% and mean scores below 4. Depression prevalence rates ranged from 7% to 17%, with a mean score below 4. Most patients with depression were not previously recognised as being depressed. CONCLUSIONS: Few publications reported on anxiety and/or depression in hospitalised patients aged ≥ 80 years using HADS. A gap in the knowledge base has been identified. IMPLICATIONS: Anxiety and depression are mental health conditions that can lead to adverse events and strongly affect aging. Increased understanding of the role that these conditions have on hospitalised patients ≥ 80 years is important for nurses when in contact with this patient group. IMPACT: There is a need for more studies to generate evidence regarding anxiety and depression in an increasingly common and challenging hospital population by building upon evidence that is based on validated instruments such as the Hospital Anxiety and Depression Scale. REPORTING METHOD: The PRISMA guideline was followed, and the review registered in PROSPERO (Registration number CRD 42022380943). PATIENT CONTRIBUTION: No patient or public contribution. TRIAL REGISTRATION: CRD 42022380943.