Fat embolism is a definite, well established disease entity which is neither new nor infrequent.1 Over seventy-five years ago the condition was reported in man; its clinical aspects were noted, its physiologic alterations described and the postmortem observations recorded. Many articles have appeared in the literature since that time covering the various aspects of the condition. From them one is able to draw a fairly definite and accurate picture of what happens in a person in whom this complication develops. The term complication is used because in nearly all cases it is a complication of some other condition in the body, the exception to this being fat embolism due to intramuscular injections of medicated oils that inadvertently enter the blood stream. The conditions to which it is a complication are diversified and include osteomyelitis, nephritis, burns, orthopedic operations, operations on and injuries to fatty tissues, fractures, contusions and degenerative