Pulmonary embolism (PE) by occlusion of the pulmonary arterial bed may lead to acute life-threatening but potentially reversible right ventricular failure, one of the most severe complications of thoracic surgery. Still, the incidence of acute pulmonary embolism after surgery is reduced by comprehensive anticoagulant prevention, improved surgical techniques, appropriate perioperative management and early ambulation. However, there is difficulty in diagnosing PE after thoracic surgery due to the lack of specific clinical manifestations. So that optimal diagnostic strategy and management according to the clinical presentation and estimated risk of an adverse outcome is fundamental.