Hyperhidrosis refers to excessive and uncontrollable sweating beyond that is required to return body temperature to normal. Although a broad spectrum of treatment modalities are available including topical and systemic therapies, iontophoresis, and surgical interventions, their efficacy are usually short-term or are associated with unacceptable side effects. Recently, chemodenervation using botulinum toxin has emerged as a safe and effective treatment for both primary palmar and axillary hyperhidrosis in several clinical trials. In this article, we utilized the scale developed by the Therapeutics and Technology Assessment (TTA) subcommittee of the American Academy of Neurology evaluating current evidence supporting the use of botulinum toxin for the treatment of primary focal hyperhidrosis. As a result, there is a strong evidence to support the efficacy of botulinum toxin type A in axillary (Level A evidence) and palmar (Level B evidence) hyperhidrosis.