Seventy-seven patients with blepharospasm unresponsive to other forms of therapy were treated with botulinum A toxin. The drug was injected into the orbicularis oculi muscle of both upper and lower eyelids and, in some patients, into the brows and upper part of the face as well. A total of 192 treatment sessions were given, with follow-up ranging from four weeks to 18 months. Orbicularis muscle spasms decreased markedly over the first five days following injection, both in patients with essential blepharospasm and in those with hemifacial spasm. Beneficial effect was temporary, however, and repeated injections were required for sustained relief. Fifty-two patients received multiple treatments, ranging from two to eight injections each, with a mean duration of benefit of 11.8 weeks. Results of subsequent injections were similar to the first in rapidity of onset, degree of benefit, and duration of effect. Complications were local, mild, and transient, and no systemic side effects were encountered.