Eighteen patients with glabellar frown lines were treated with C. botulinum-A exotoxin. Sixteen of the 17 patients followed showed improvement for periods ranging from 3 months to 11 months. Side-effects were minimal and transient. Because C. botulinum-A exotoxin therapy of glabellar frown lines treats the underlying cause of these lines, it is more effective than soft tissue augmentation although this improvement is temporary. Treatment with C. botulinum-A exotoxin is a simple, safe procedure.