Nonunion of the ankle malleoli is extremely rare these days. This is probably due to the fact that primary osteosynthesis is performed in ankle fractures instead of the conservative treatment given up to 20 years ago. Today nonunions of the malleoli are seen, if at all, is infected cases after surgical procedures. Noninfected, stable and painless nonunions usually do not need any surgical correction. In painful cases, small fragments, especially of the medial malleolus, should be resected; larger fragments should be stabilized with two 3.5-mm cancellous screws. Alternatively, the tension banding technique, especially after Weber A fracture, produces high compression in the area of nonunion. In cases of additional bony defects, a local upside down cortical-cancellous bone graft should be performed in addition. In summary, the therapeutic approach requires exact remodeling, bone-grafting and stabilization. Infected nonunions with loss of bone mass should be treated according to the guidelines for osteitis therapy.