After conservative treatment nonunion (pseudarthrosis) of the clavicle can be observed approximately 10 times more frequently (15-24%) than after surgical treatment (1.4%). Risk factors include the fracture location, displacement, fracture type, sex, the severity of the accident and refractures. The diagnosis of pseudarthrosis of the clavicle can be made by a thorough medical history, clinical examination and imaging procedures. The main symptom is pain, often accompanied by malalignment, instability, neurological symptoms and restricted mobility of the affected shoulder. The diagnosis is confirmed by X‑ray images and, if necessary, a computed tomography (CT) scan. Pseudoarthrosis is classified according to the morphological appearance in X‑ray images and the cause. A differentiation is made between vital and nonvital pseudarthroses. Only symptomatic pseudarthrosis requires treatment. Nonoperative methods, such as magnetic field therapy or ultrasound are minimally effective. Surgical interventions are indicated for pain, movement restrictions or neurovascular problems. The goals of surgical treatment are to restore the vitality, bone length and stability through angular stable osteosynthesis. In cases of surgical pretreatment the anteroinferior plate position offers a good alternative to the superior plate position. In some cases double plating osteosynthesis can be indicated. Autogenous bone material, allogeneic substitute material and vascularized grafts are used for bony defects. Surgical treatment shows high rates of healing but also carries an increased risk of infection.