Although acute idiopathic facial paresis is often labelled "Bell's palsy", historical studies show that Nicolaus Anton Friedreich (1761-1836) from Würzburg was the first physician to describe the typical symptoms of the disorder in 1797, approximately 24 years prior to the paper published by Sir Charles Bell. Diagnostics has now improved to the extent that acute idiopathic facial palsy can more frequently be assigned to etiologies caused by inflammatory disorders. Herpes simplex virus type I and Borrelia burgdorferi are particularly relevant. Underestimation of the degree of paresis is, particularly in children, a drawback of the clinical examination. "Incomplete eyelid closure" is not a reliable indicator of remaining nerve function. For this reason complete electromyography (EMG) is recommended in all cases of severe facial paresis. Since electroneurography does not reliably reflect the degree of denervation present, needle EMG is preferred. The therapy of the facial palsy of unclear etiology is still not well defined. Nevertheless, we recommend that a combined treatment should be used early, at least in patients with disfiguring pareses. Combinations may consist of cortisone, virostatic agents and hemorrheologic substances and possibly antibiotics. Surgical decompression of the facial nerve remains controversial, since positive surgical results lack statistical support. Individual instructions for facial exercises, massage and muscle relaxation can support rehabilitation and possibly reduce the production of pathological synkinesia. Electrical stimulation should not be used. There are a number of possibilities available to reduce the effects of misdirected reinnervation, especially the use of botulinum-A-toxin. However, intensive diagnosis and therapy in the early phase of paresis are decisive in obtaining a favorable outcome. Further refinements in rehabilitation and comparative multicenter controlled studies are still required for future improvements in affected patients.