A 34-year old female underwent lung biopsy under video assisted thoracoscopic surgery for lymphangioleiomyomatosis (LAM). She had obstructive lung disease, and had a large amount of ascites. We did not treat her lung disease pre-operatively because her pulmonary symptom was not severe. During operation, anesthesia was uneventful even during one lung ventilation period. After surgery, she showed hypoxemia and fell into respiratory failure. We suspect that respiratory failure was induced by ascites in this case. Respiratory failure would have come from restrictive ventilatory impairment caused by a large amount of ascites in addition to the obstructive ventilatory impairment. Care should be taken on respiratory function in case of LAM with ascites during perioperative period.