1. The posterior Monteggia fracture usually conforms to a typical pattern. 2. Its incidence is greatest among middle-aged women. 3. The mechanism of the injury is probably similar to that of the dislocated elbow. Excessive rotation of the forearm plays no part in its production. 4. Internal fixation of the ulna combined with excision of the whole radial head, or of its detached segment, is suggested as the treatment of choice. 5. The functional results after operation are excellent, but some slight permanent restriction of movement is to be expected.