Background: Critically ill patients after Intensive Care Unit (ICU) discharge may present disability in their cognitive and physical functions. Objectives: To investigate the quality of life (QoL) of both COVID-19 and non-COVID-19 patients following ICU discharge, lung function, and physical performance of participants. Methods: This study was prospective and conducted between 2020 and 2021 in the “X” hospital. If patients were Mechanically-Ventilated (MV) > 48 h, they were included. Results: Fifty COVID-19 and seventy-two non-COVID-19 participants were included in this study. The mean (SD) of the total SF-36 scores at COVID-19 patients at hospital discharge and 3 and 12 months were 46.5 (14.5), 68.6 (17.8), and 82.3 (8.9) (p < 0.05), while non-COVID-19 participants were 48.5 (12.1), 72.2 (9.9), and 82.7 (5.4) (p < 0.05). The forced expiratory volume in one second (FEV1) and 6-minute walking distance (6MWD) were assessed at 3 and 12 months and significantly improved over 12 months. Conclusion: The QoL of COVID-19 patients improved significantly over time as FEV1 and 6MWD.