Acute idiopathic pulmonary hemorrhage in infants (AIPHI) is characterized by a sudden onset of pulmonary hemorrhage in previous healthy infants. Evidence of pulmonary hemorrhage may present as hemoptysis or a finding of blood in the nose or airway with no evidence of upper respiratory or gastrointestinal bleeding. Patients presenting with acute, severe respiratory distress or failure, and those requiring mechanical ventilation and often demonstrate bilateral infiltrates by chest radiography. We report a case of AIPHI which developed during the induction of anesthesia. A 3-month-old male infant received right herniorraphy under general endotracheal anesthesia. After intubation, blood tinged fluid was aspirated using an endotracheal tube during operation. Chest radiography showed bilateral ground glass opacity. We transferred the patient to the ICU and applied conventional mechanical ventilation. However hypoxemia and respiratory acidosis were persisted. We then switched to a high frequency ventilator (HFV), the hypoxemia and respiratory acidosis were corrected. The patient was transferred to the general ward on the 7th postoperative day.