Monteggia fractures consist of an ulna fracture accompanied by radial head dislocation. Such fractures are easily overlooked due to the prominence of the ulna fracture. Earlier studies have reported on the results of treating Monteggia fractures in children and adults even though this type of fracture is different in these two patient populations. As such they should be considered as separate entities due to the different injury pattern, the prognosis, and the preferred method of treatment. For a good postoperative result, an early detection of the Monteggia dislocation, an efficient operative treatment of the ulna fracture, and reposition of the radial head are essential. The goal of reconstruction is an early mobilization within a stable arc of motion. Here, we provide an overview of the classification of Monteggia fractures, the mechanism of injury, and treatment options with the aim of providing sufficient information to reduce the possibility of underestimating forearm injuries in adults.