Abstract Botulinum toxin type A is a safe and effective method for treating focal hyperhidrosis, providing longer-lasting results than topical treatments without the necessity of invasive surgical procedures. Although more useful for axillary hyperhidrosis, botulinum toxin injections can also be effective in treating palmar and plantar disease. The effects of botulinum toxin last for six to nine months on average, and treatment is associated with a high satisfaction rate among patients. In this article, the authors discuss their preferred methods for treating axillary, palmar, and plantar hyperhidrosis. This article serves as guide for pretreatment evaluation, injection techniques, and posttreatment care. Hyperhidrosis is defined as sweating in excess of what is required to regulate body temperature. As many as 1.3 million Americans are diagnosed with severe hyperhidrosis.1 Affected patients are hampered in occupational and social situations, leading to diminished physical and emotional well-being, difficulty in personal relationships, and social stigmatization.2-6 Primary hyperhidrosis can be treated both surgically and nonsurgically. First-line nonsurgical therapies involving topical antiperspirants such as aluminum chloride are often short-acting and require frequent reapplication, are ineffective in reducing sweat production, and are intolerable secondary to irritant dermatitis.7,8 Surgical procedures include endoscopic transthoracic sympathectomy (ETS), arthroscopic shaving of the glands, and excision of sweat glands. These treatments are invasive, may be associated with serious complications and high recurrence rates, and require operative fees, time to recuperate, and anesthesia.9-13 Therefore, the ideal treatment would be safer and less invasive than surgery, as well as longer-lasting and more tolerable than topical agents, and it would result in high patient satisfaction rates. With these criteria in mind, botulinum toxin type A has emerged as an important treatment option for patients plagued with focal hyperhidrosis.