Elbow flexion plays a key role in the overall function of the upper extremity. In the case of unilateral complete brachial plexus lesion, restoration of elbow flexion will dramatically increase the patient's chances of regaining bimanual prehension. Furthermore, depending on the type of reconstruction, stability of the glenohumeral joint as well as some supination function of the forearm can be restored to a varying degree at the same time. Depending on the level of brachial plexus lesion and/or reinnervation, different reconstructive procedures are available. In order to select the best treatment option for the patient it is necessary to known the extent of the lesion of the brachial plexus and/or ventral upper arm muscles, to time the operation appropriately, to be aware of all treatment possibilities and to recall the special problems of tendon transfer for brachial plexus patients. Our concept is based on our experience with more than 1100 patients presenting a brachial plexus lesion between 1981 and 1996 and treated in our institution. There were 528 operative revisions of the brachial plexus. Some 225 patients underwent secondary muscle/tendon transfers. In 35 patients elbow flexion was reconstructed by bipolar latissimus dorsi transfer (n = 10), triceps-to-biceps transfer (n = 15), modified flexor/pronator muscle mass proximalization (n = 6) and multiple-stage free functional muscle transfer after intercostal nerve transfer (n = 4).