Diaphyseal forearm fractures represent a spectrum of injury patterns that include isolated radial shaft fractures, isolated ulnar shaft fractures, both-bone forearm fractures, Galeazzi fracture-dislocations, and Monteggia fracture-dislocations. Although less common than distal radius fractures, diaphyseal forearm fractures are still a frequently encountered clinical entity seen by orthopaedic surgeons, both as isolated injuries and in the patient with polytrauma. It is important to review the epidemiology of diaphyseal forearm fractures and the classification systems used to describe them, as well as to discuss the principles of the initial evaluation and management of these fractures. It is important to know the indications for nonsurgical and surgical management, along with the goals of surgical management, options for internal fixation, and surgical approaches to the forearm.