Background: For critically ill patients with coronavirus disease MESHD 2019 (COVID-19) who require intensive care unit (ICU) admission, mortality rates vary widely depending on many factors, among which hospital resources and clinical setting seem important. We sought to determine the outcome of critically ill patients admitted in the usual multidisciplinary ICUs of a big referral for COVID-19 tertiary-care hospital with adequate resources.Methods: We performed a prospective observational study of all adult TRANS patients with COVID-19 consecutively admitted to four COVID-designated ICUs at Evangelismos Hospital, Athens, Greece, from March 11 to April 27, 2020.Results: Among 50 critically ill patients, ICU and hospital mortality for the entire cohort was 32% (16/50), whereas 66% (33/50) of patients were discharged alive from the ICU and 2% (1/50) were still treated in the ICU until June 16, 2020. ICU and hospital mortality for those who received invasive mechanical ventilation was 39% (16/41). Patients who eventually died had already increased risk of death MESHD on ICU admission, as suggested by the high values of the Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores, the presence of current malignancy and occurrence of cardiac arrest HP in 44% (7/16) of patients, and the general need for circulatory support by noradrenaline. Median PaO2/FiO2 on ICU admission for the entire cohort was 121 mmHg [interquartile range (IQR), 86-171 mmHg] and most patients had moderate and severe acute respiratory distress HP syndrome MESHD (ARDS) according to the Berlin Definition. The primary cause of death MESHD of all patients was multi-organ failure, most commonly due to sepsis MESHD sepsis HP, whereas none died from refractory hypoxemia HP, neurologic dysfunction or withdrawal of life support. Hospital stay was long in patients who survived [median 24 days (IQR, 15-35 days)] and was frequently complicated by bacteremias MESHD bacteremias HP [36% (12/33)].Conclusion: Severely ill COVID-19 patients with moderate and severe ARDS may have equal or even lower mortality rates compared to ARDS due to other causes, when they are admitted in general ICUs with experienced and adequate staff without limitations in hospital resources, where established ARDS therapies are used.