A review of the literature reveals that with conventional treatment alone or in combination with secondary muscle/tendon transfer, about 4-43 % of cases show incomplete recovery with severe functional and/or aesthetic impairment (group III). If these patients undergo early microsurgical brachial plexus revision, regeneration without significant functional and/or aesthetic impairment (shift from group III to group II) can be achieved in 80-90 % of cases. Moreover, microsurgical reconstruction of the brachial plexus increases the possibilities of secondary muscle/tendon transfers. Therefore, provided patient selection is good, severe obstetrical brachial plexus injuries should be scheduled for early microsurgical revision. There is no need to wait for a frustrating spontaneous recovery. Our concept is based on our experience with more than 1100 patients presenting with brachial plexus lesions between 1981 and 1996 and treated in our institution. There were 217 obstetrical brachial plexus lesions, 133 of which were treated conservatively. In 84 cases operative treatment was necessary. Fifty-one cases underwent early revision of the brachial plexus, and secondary tendon transfer was done in 33 patients.