Fat embolism syndrome is manifested by the fat globule systemic presence involved in a motor vehicle in the pulmonary and circulation. A 34-year-old man was accident with a fracture of the left femur and avulsion fracture of the left posterior cruciate ligaments. He developed signs and symptoms that suggested an early diagnosis of fat embolism syndrome. Intravenous methylprednisolone administration was administered as part of the treatment. The role of methylprednisolone in a patient with fat embolism syndrome is controversial due to unproven effectiveness. In this case, fat embolism syndrome after a femur fracture was treated successfully with methylprednisolone. Keywords: fat embolism syndrome, methylprednisolone, femur fracture.