A 69-year-old man with a history of diabetes mellitus and benign prostatic hypertrophy was admitted to our medical unit with a 1-week history of fever, runny nose, and shortness of breath. Chest X-ray revealed bilateral diffuse ground glass opacities in both lung fields. The patient had type 1 respiratory failure and required non-invasive positive pressure ventilation to maintain oxygenation. The patient was given ceftriaxone 1 g every 12 hours, and doxycycline 100 mg and oseltamivir 75 mg twice daily. He was transferred to the intensive care unit and intubated due to severe acute respiratory distress syndrome (ARDS). The patient's nasopharyngeal swab was tested by polymerase chain reaction and the result was positive for influenza A virus H1 RNA. His clinical course was further complicated by septic acute kidney injury that necessitated continuous venovenous haemofiltration. His lungs gradually improved with supportive measures including prone ventilation and muscle paralysis for 48 hours. The fractional oxygenation requirement improved from 1.0 to 0.4 between day 1 and day 8 of admission and chest X-ray showed improving aeration of both lungs.