We describe a patient who experienced systemic adverse effects after the injection of botulinum toxin type B (Myobloc) to treat palmar hyperhidrosis. The adverse effects included blurry vision, indigestion, and a severe dry throat associated with dysphagia. Although systemic adverse effects have been described in the medical literature after the use of botulinum toxin type B for the treatment of cervical dystonia, to our knowledge, it has never been described as being associated with the treatment of palmar hyperhidrosis.