Stereotypic movement disorder (SMD) consists of repetitive, non-functional motor behaviour that interferes with daily living or causes injury to the person. It is most often described in patients with mental retardation. However, recent evidence indicates that this condition is common among otherwise normal individuals. This case study describes a patient with new-onset SMD occurring after subdural haematoma and brain injury. SMD has rarely been reported after acquired brain injury, and none have documented successful treatment. The current psychiatric literature regarding neurochemistry, neuroanatomy, and treatment of SMD are reviewed with particular application to one patient. Treatment options include serotonin re-uptake inhibitors, opioid antagonists and dopamine antagonists. SMD has been under-appreciated in intellectually normal individuals, and may also be unrecognized after brain injury. Further investigation is needed in this area, which may benefit other individuals with SMD as well.