[Purpose] We report a case of severe pneumonia who acquired early mobilization and self-care while on mechanical ventilation (MV), and improved exercise tolerance with positive airway pressure therapy (EzPAP) after MV withdrawal. [Participant and Methods] The subject was an 82-year-old male who was on MV in an intensive care unit for X days due to severe pneumonia and septic shock. From day X+5, the case was weaned at an early stage with walking under MV, and self-care instruction, such as oral care and grooming, was started in cooperation with nursing staff. After MV withdrawal, positive airway pressure therapy (EzPAP) was started on day X+16 to relieve atelectasis. [Results] The subject became independent in self-care on day X+9 and was able to walk under supervision. The 6-minute walking distance improved from 100 m (X+18 days, nasal cannula 4 L/min) to 355 m (X+35 days, no oxygen). [Conclusion] Self-care assistance, such as in this case, should be a multidisciplinary effort, and combined use of EzPAP should be considered to eliminate atelectasis and improve exercise tolerance.