Objectives: Oldest-old patients may have an unusual SARS-COV2 presentation that can jeopardise diagnosis and management. The aim of this study was to compare the clinical characteristics and outcomes of oldest-old (≥85 years) and old patients (75-85 years) admitted with COVID-19 to Belgian hospitals during the first wave of the pandemic. Methods: We conducted a multicentre, retrospective, observational study in ten Belgian hospitals. We reviewed the electronic clinical records of patients ≥75 years hospitalised with COVID-19 from March to June 2020. Results: A total of 986 patients were placed on the register (old group: n = 507; oldest-old group: n = 479). Before hospitalisation, the oldest-old (OO) group presented with more geriatric syndromes including comorbidities, frailty, falls, cognitive impairment, and incontinence. At admission, the OO group presented with less cough, less headache, and less fever but significantly more delirium than old (O) group. Members of the OO group were admitted less frequently to intensive care units (ICUs). A geriatrician was consulted to help in the decisionmaking process more often for the OO group. The global mortality of the cohort was 47%, with no difference between the two groups. Patients in the OO group were more often institutionalised after hospitalisation and less often referred for rehabilitation. Conclusions:The OO patients presented with more geriatric syndromes that make them vulnerable to dependence and institutionalisation after a hospital stay, without having a higher mortality rate than O patients. Geriatrician expertise is necessary in the management of frail older patients.