Atelectasis is a relatively common complication following surgery in anesthetized patient with respiratory symptoms, but rarely occur in normal healthy patient. Anesthesiologists must be wary to prevent atelectasis, because it may lead to hypoxia during and after the operation. This case reports a healthy patient without previous respiratory symptoms who developed left lower lobar atelectasis after general anesthesia. Vigorous chest physiotherapy including intended coughing, deep breathing, chest percussion and vibration under postural change was effective. Therefore, vigorous chest physiotherapy is essential part of early treatment modalities for atelectasis in postoperative recovery room.