General endotracheal anesthesia with mechanical ventilator is a common anesthetic practice since introduction of various anesthetic ventilator. A mechanical not only deoreases workload but also allows the anesthesiolosist to better nonitor and manage the patient during the operation. However, acoidental complications can be encountered during the wse of ventilator as with all other modern equipments. Several authors have described that increased pulmonary pleasure from poaitive pressure ventilation mar lead to alveolar rupture with subsequent dissection of air along the vascu- lar structure of the lung into the hilum and then into the tissue plane of the mediastinum. We report a case of pneumomediastinum, pneumoperitoneum and subcutaneous emphysema without pneumothorax which occured during discoidectomy under the endotracheal ventilator anesthesia.