A review of our century's efforts to overcome nerve defects reveals the conclusion that today microsurgical techniques and interfascicular nerve grafting offer the best chances to get success in peripheral nerve repair. There exists a theoretical grading system of Sunderland, which enables us to understand the very different factors which might influence the sprouting of nerve fibers within the damaged or repaired nerve segments. But in practice, the indication to operate always depends on our own decision. The neurological status and electrophysiological tests can only sometimes facilitate our treatment and judgement on peripheral nerve lesions. The basic principles of microsurgical nerve repair are still valid. Modern techniques have resulted in better prognosis. Vast mobilization to achieve neurorrhaphy by force is obsolete today. Epineural trunk-to-trunk-suture is only allowed after clean cut-injuries. In all other cases we have to prefer a repair by autologous grafting. But some factors still remain which limits our efforts, such as muscle degeneration depending on time interval or ischemic fibrosis after the lesion, direct trauma to the muscle substance or a lesion in the region of nerve ramifications.