Traumatic adult brachial plexus injuries typically cause immediate loss of upper limb function. Timely multidisciplinary treatment in specialized centres often results in a useful helper arm. Both the patient and the surgical team can benefit from an open discussion to set realistic expectations. Surgical reconstruction is customized for each patient, considering their injury factors and functional objectives. Optimizing pain control, adherence to procedure indications and using meticulous surgical techniques help minimize the risk of failing to meet the patient’s goals. The need for potential alternative treatment(s) if the desired result is not achieved should be detailed before the initial reconstruction. This review discusses late treatment options, including tendon transfers, joint fusions, free functioning muscle transfers and prosthetics, for managing the failed primary reconstruction of the traumatic adult brachial plexus.