We illustrate a rare complex dislocation of the elbow involving a posterior ulno-humeral dislocation associated with open diaphyseal fracture of the ulna, radial shaft fracture, Type 1 coronoid fracture and neuropraxia of the deep branch of the radial nerve. The isolated ulno-humeral dislocation without radio-capitellar involvement, and ulnar diaphyseal fracture, makes this "reverse Monteggia" type of injury pattern very unique. This patient was managed with an initial reduction of his ulno-humeral joint and stabilization of his radius and ulna fractures. He underwent a delayed medial collateral ligament reconstruction a few days later. His fractures went on to unite fully, his elbow joint remained stable, and he achieved good range of motion of his elbow.