Neurosurgery has long had a role in the treatment of disorders of muscle hyperactivity. This article discusses the use of selective peripheral neurotomy for the treatment of focal and multifocal spasticity, selective dorsal rhizotomy for alleviation of more generalized spasticity most often in the setting of cerebral palsy, dorsal root entry zone lesioning for cases of severe spasticity in a nonfunctioning limb, and deep brain stimulation for the treatment of dystonia. For each procedure, relevant pathophysiology and basic surgical anatomy and technique are addressed. Additionally, relevant aspects of patient selection, efficacy data, and complications of these procedures are discussed.