This paper retrospectively analyses the clinical data of 65 consecutive cases of hemifacial spasm. A benign etiology was clinically evident in the majority of cases. Neuroradiologic investigation ruled out serious intracranial pathology in atypical cases. Trials of oral medication in 26 patients were consistently unsuccessful. Fifty-one patients had repeated lid and facial muscle injections of botulinum toxin during a period of 8 years. The mean duration of effective relief from spasm following an initial treatment was 18.9 weeks. This effect did not diminish with repeated injections.