From 1950 through 1984, 123 patients underwent surgical treatment of blepharospasm at the Mayo Clinic. During this period, four different operations (proximal and distal neurectomy and two types of myectomy) were used. Significant recurrent or residual blepharospasm was observed more frequently (P less than 0.01), and need for subsequent operations was greater (P less than 0.01), among patients who had undergone distal neurectomy than among those who had had myectomy. These data support the view that myectomy is a more effective procedure than neurectomy. Initial results with botulinum toxin injection seem to indicate that it is an effective short-term treatment for blepharospasm. However, its long-term efficacy and safety need further study, as does the role it should play in combination with myectomy.