The object of this study was to determine whether brow elevation occurs as a result of paralysis of brow depressors after botulinum toxin injection. This prospective study was designed with pretreatment and posttreatment outcome evaluation with statistical analysis. Twenty-seven consecutive patients were injected into brow depressor muscle directly. Botulinum toxin was injected into the glabellar area (5U), the supralateral eyebrow (2.5Ux2), the crow's feet (4Ux2). All patients were evaluated 2 weeks after treatment. The outcomes were measured by change in brow elevation; 1) brow to medial canthus, 2) brow to midpupil, 3) brow to lateral canthus, 4) interbrow distance, 5) brow to hairline. The average brow elevation were noted from the medial canthus (0.92mm+/-0.58mm, p<0.001), midpupil (1.42mm+/-0.61mm, p<0.001), lateral canthus(1.37mm+/-0.79mm, p<0.001). The average change were increased in interbrow distance(0.7mm+/-0.46mm, p<0.001) and decreased in brow to hairline(0.69mm+/-0.81mm, p<0.001). Botulinum toxin is a safe and effective treatment for chemical brow lift. The elevation in the medial, central and lateral brow can produce an aesthetically pleasing female brow with desirable shape and height. Although the endoscopic brow lift is more effective and able to predict the change of the brow shape and height, this procedure may be considered a simple and safe alternative to surgical brow elevation.