Twenty-six patients were treated for hemifacial spasm by selective facial neurectomy. The symptoms of hemifacial spasm can be relieved by performing extracranial selective facial neurectomy with preservation of the temporal and cervical ramus. The facial nerve branches have been identified by selective electrical stimulation over the nerve, which evokes responses from the corresponding facial muscles. Selective facial neurectomy were completed when stimulation of the nerve produces minimal movement in the orbicularis oculi muscle while normal contractions appear in the frontal region and lip portion. The results of surgery 2 years postoperatively indicated that the complete disappearance of hemifacial spasm was achieved in 65.6 percent of the patients. A slight relief was achieved in 15.5 percent of the patients. Unsatisfactory results were obtained in 11.5 percent. No spasm recurred in 7.5 percent of patients, but paralysis of frontal muscle persisted.