Introduction: Obesity is one of the mainly risk factors to develop severe COVID-19 ADRS but, it is not clear if its respiratory mechanics adaptations can contribute with this critical clinical condition. The aim of this study was to identify if the mechanical respiratory data on ICU admission of intubated obese patients with COVID-19 could influence the hospitalization outcome at discharge or death. Methods: We included patients admitted in the Covid-ICU, with BMI?30kg/m2, older than 18 years old and mechanically ventilated. Respiratory mechanics data were obtained on ICU admission, after orotracheal intubation. We analyzed peak pressure (Ppeak), plateau pressure (Pplat), static compliance (Cst), airway resistance (Raw) and ventilatory ratio (VR). Results: Eighty four patients were included and allocated in the Discharge Group (n= 45) and Death Group (n= 39). Death Group were older than Discharge Group (62,82±13,85 and 49,18±12,85 years old; p<0,0001), without difference between BMI (39,12±10,5 e 38,31±6,47 kg/m2; p=0,572). Respiratory mechanics data were not different between groups: Ppeak (29,87±5,17 e 28,14±3,93cmH2O; p=0,087); Pplat (24,47±4,03 e 23,21±3,44cmH2O; p=0,223); Cst (33,96±11,63 e 32,54±8,91cmH2O; p= 0,773); Raw (12,29±2,59 e 12,93±3,42cmH2O/L/s; p=0,326) for Death Group and Discharge Group, respectively. VR was the only variable that differed between groups (2,24±0,63 and 1,96±0,77; p=0,02). Conclusions: Although there was no difference between the static and dynamic respiratory mechanics data; VR was higher in the death group, indicating worse ventilation efficiency with greater probability of the worst outcome.