text: Long term clinical follow up of patients suffering from moderate to severe COVID 19 infection a monocentric prospective observational cohort study Various symptoms and considerable organ dysfunction persist following infection with severe acute respiratory syndrome coronavirus 2 SARS CoV 2 Uncertainty remains about the potential mid and long term health sequelae This prospective study of patients hospitalized with coronavirus disease 2019 COVID 19 in Liège University Hospital Belgium aimed to determine the persistent consequences of COVID 19 Patients admitted to the University Hospital of Liège with moderate to severe confirmed COVID 19 discharged between 2 March and 1 October 2020 were recruited prospectively Follow up at 3 and 6 months after hospital discharge included demographic and clinical data biological data pulmonary function tests PFTs and high resolution computed tomography CT scans of the chest In total 199 individuals were included in the analysis Most patients received oxygen supplementation 80 4 Six months after discharge 47 and 32 of patients still had exertional dyspnoea and fatigue PFTs at 3 month follow up revealed a reduced diffusion capacity of carbon monoxide mean 71 6 18 6 and this increased significantly at 6 month follow up P 0 0001 Chest CT scans showed a high prevalence 68 9 of the cohort of persistent abnormalities mainly ground glass opacities Duration of hospitalization intensive care unit admission and mechanical ventilation were not associated with the persistence of symptoms 3 months after discharge The prevalence of persistent symptoms following hospitalization with COVID 19 is high and stable for up to 6 months after discharge However biological functional and iconographic abnormalities improved significantly over time 