This study was designed to quantitatively characterize the time course of facial palsy and the relationship between electroneurography and the facial nerve grading percentage as a function of onset time. Bilateral electroneurographic recordings during different stages in the course of the disease were repeated and compared with categorized videotaped facial movements using the House-Brackmann facial nerve grading system in 32 patients with Bell palsy. Preliminary results of this study demonstrate a time gap between the percentage of electroneurographic response and the category of the facial nerve grading system during the same period of disease progress. A theoretical model of the time course and specific patterns regarding the recovery of facial function is established. The theoretical time course of facial palsy is divided into 3 stages; preclinical, clinical, and postclinical. Based on the time course of electroneurographic and facial grading functions, the period between 10 and 14 days after onset was found to be most valuable for prediction of recovery. According to this theoretical model, a given time course pattern based on the results of serial electroneurographic recordings provides reliable prognostic information on recovery from Bell palsy.