Fat Embolism is a rare complication of multiple long bone fracture or extensive soft tissue injury. The pathogenesis of fat embolism has been poorly understood and still its definite pathogenesis, diagnosis and treatment were not fully established. Recently fat embolism considered as a post traumatic respiratory failure. Monitoring of blood gas is required for early diagnosis and respiratory supportive treatment with continued minitoring is necessary until resolution. Fifteen cases of fat embolism treated at from September 1979 to October 1981 Eul Ji General Hospital were clinically analized. Among the fifteen cases, fourteen were recovered without sequalae and one was expired ten days after trauma.