Pulmonary thrombo-embolism in operating room is one of the important cause of morbidity and mortality in patients undergoing femur neck fracture surgery. However, the diagnosis of pulmonary thromboembolism may not be easy because sudden shock can have many different causes (e.g. myocardial infarction, hypovolemia, pneumothorax, non-cardiogenic pulmonary edema, pulmonary thrombo- embolism) and specialized diagnostic tools are not readily available in the operating room. Rapid and accurate diagnosis of pulmonary thromboembolism is very important in outcome of patients. We report a case in which pulmonary thromboembolism under spinal anesthesia occured just before the beginning of operation.