Survivors of severe COVID-19 with ICU admission show a significant post-infection decline in functional capacity as measured by the Duke Activity Status Index (DASI) score compared to pre-infection. The study retrospectively evaluated DASI changes in 3 patients hospitalized due to COVID-19. A lower DASI score after COVID-19 was associated with the presence of pleural effusion and lung ultrasound abnormalities. A strong correlation was found between the duration of intubation, length of hospital stay and DASI variation. The DASI is a validated tool for assessing cardiopulmonary fitness and preoperative risk. Severe COVID-19 thus has a permanent impact on functional capacity. Anesthesiologists should include DASI in the preoperative assessment of these patients for better risk stratification and perioperative outcomes.