Spasticity is common in many neurological disorders, such as stroke and multiple sclerosis. It is part of the upper motor neurone syndrome manifesting as increased tone, clonus, spasms, spastic dystonia and co-contractions. The impact of spasticity varies from it being a subtle neurological sign to severe spasticity causing pain and contractures. Existing spasticity can be worsened by external factors such as constipation, urinary tract infections or pressure ulcers. Its management involves identification and elimination of triggers; neurophysiotherapy; oral medications such as baclofen, tizanidine and dantrolene; focal injection of botulinum toxin, alcohol or phenol, or baclofen delivered intrathecally through a pump; and surgical resection of selected dorsal roots of the spinal cord. This article reviews the current understanding of pathophysiology, clinical features and management of spasticity.