Bell's palsy is the most common acute facial paralysis with its causes still unclear. At present, the most widely accepted causes are viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. Unclear causes lead to unidentified treatments. Most therapeutic methods are simply symptomatic treatment. Fortunately, the pathomechanism of Bell's palsy is relative clear, involving herpes simplex virus (HSV) reactivation within the geniculate ganglion, followed by inflammation and entrapment of the nerve in the bony foramen. This makes symptomatic treatment possible. But the therapeutic effects are not quite satisfactory. Therefore, novel etiological and therapeutic concepts are urgently needed. According to our clinical observation and some facts that do not favor the viral infections theory, we can conclude that all Bell's palsy is not related to viral infections, some even may have relations to bacterial infection. As far as blood routine examination is concerned, though lymphocyte increasing can be seen in most patients with Bell's palsy, there are cases with normal lymphocyte but increased neutrophil. Also, antibiotic treatment in these patients could accelerate recovery to some extent. These results indicate that Bell's palsy in these patients may be caused by bacterial infection.