The effectiveness of botulinum toxin for the treatment of Frey's syndrome is demonstrated. Since December 1993, 14 patients with severe symptomatic gustatory sweating have been treated at the ENT Department, University of Göttingen. Botulinum toxin A (approximately 0.5 U/cm2) was injected intracutaneously into the affected skin area as determined by Minor's starch iodine test. Gustatory sweating in the treated skin area ceased completely within 2 days and did not reappear during the period of following (13 months maximum follow-up). There were no side effects. Findings show that local botulinum toxin injections are a highly effective, safe and minimally invasive treatment for Frey's syndrome. Moreover, this could be a new therapeutic tool for other forms of hyperhidrosis.