Pulmonary embolism is not uncommonly encountered in orthopedic patients with high risks, such as prolonged immobility, obesity, past or family history of thromboembolism, pelvic and long bone fractures. Here we report a young male patient with a residual cerebral arteriovenous malformation post-craniotomy suffered from acute severe hypoxemia after sustaining a simple fracture of the left femur shaft from a motorcycle accident. The emergent surgery was deferred in view of suspectable pulmonary embolism. Under supportive treatment, the condition spontaneously resolved, and the surgery was later performed uneventfully. To the best of our knowledge, this was the first instance that a pulmonary embolism (suspected subacute fat embolism syndrome) which ran in a natural course to spontaneous resolution was observed. We would like to report our clinical observation, and discuss the principle of anesthetic management in the text.