The patient was a 15-year-old girl who received laryngotracheal separation. Influenza A was detected upon examination due to fever (41°C) and dyspnea; the patient was admitted, and it was suspected that the onset of ARDS occurred subsequently. The patient was admitted to the ICU of our hospital for respiratory management. However, because an amelioration of respiratory organ symptoms was not noted, steroid pulse therapy was performed for three days from hospital day 14. P/F ratio was subsequently maintained at 200 or higher from hospital day 23. The patient was discharged from the ICU on hospital day 76.