Recurrent ulnar nonunion challenges the functional prognosis and raises major problems concerning the best therapeutic strategy to follow. The case of a female patient presenting recurrent nonunion of the ulnar diaphysis despite successive treatments is reported. The radius graft pedicled on the anterior interosseous artery from a retrograde approach obtained bone union in 3 months with no functional sequelae. For the first time, we propose a therapeutic alternative calling on a proximally pedicled anterior interosseous flap. This technique can be performed under locoregional anesthesia and does not sacrifice the main artery of the forearm. However, the size of the graft does not entirely compensate for segmentary bone loss. The radius graft pedicled on the anterior interosseus artery is an inventive technique that can solve the problem of difficult ulna nonunions without the disadvantages of vascularized fibula harvesting.