OBJECTIVE: To investigate long-term recovery after Bell's palsy and evaluate specific parameters for predicting the long-term outcome of facial weakness.STUDY DESIGN: Retrospective clinical study combined with long-term follow-up.SETTING: Tertiary care university hospital (Department of Otorhinolaryngology, Head and Neck Surgery, University of Thessaloniki, Greece).PATIENTS: Forty-four patients who were followed up 2 to 6 years (mean, 4.01 yr) after the onset of facial weakness.MAIN OUTCOME MEASURES: The failure rate of complete recovery was studied for age, initial nerve excitability test, electroneurography, initial severity of paralysis, and number of days from onset of facial weakness to the start of medical treatment.RESULTS: Thirty-two (73%) of 44 patients had a satisfactory outcome, and 12 (27%) had a nonsatisfactory recovery. Initial House-Brackmann grades V/VI and electroneurographically detected degeneration of 90% or more were shown to affect the long-term outcome of facial weakness significantly (p = 0.024 and p = 0.000, respectively).CONCLUSION: The initial severity of facial weakness and the electroneurographically detected facial nerve degeneration were found to be important factors in predicting the long-term prognosis of Bell's palsy.