Objectives To review systematically the evidence currently available on the use of botulinum toxin A in the management of gustatory sweating. Methods We conducted a systematic search of databases including PubMed (1950-December 2007), EMBASE (1966–2007), MEDLINE (1950–2007) and Cochrane library (up to December 2007). The terms used in the search included treatment, Frey's syndrome, gustatory sweating, Botulinum toxin, Botox, Dysport. Data extraction and study evaluation were performed independently by 2 reviewers and results were pooled quantitatively. Data collected included demographic details of patients, aetiology of Frey's syndrome (parotid pathology), duration of symptoms, units of injection, number of injections, commercial types of Botulinum toxin A, rate of recurrence, complications, and length of follow-up. Results There are 2 prospective studies that compared doses of Botulinum toxin (one randomized and the other non-randomized) in the management of gustatory sweating (Frey's syndrome). The other studies included prospective and retrospective case series and case reports. Pooled results from these studies on a total of 239 patients showed that the rate of recurrence or incomplete resolution of symptoms were dose-dependent. Response to treatment did not vary with the size of the affected area or parotid pathology. The demographical details did not differ in the patients with recurrence compared to those patients who were symptom-free. Complications were also not dose-related. Conclusions Botulinum toxin A is a highly effective, minimally invasive, and safe procedure for the treatment of gustatory sweating.