Chorea (χορός, dance) is a movement disorder characterized by involuntary arrhythmic movement of a forcible, rapid, jerky type that may be simple or quite complex. The differential diagnosis of chorea is wide and finding the specific cause can be a challenging task. Autoimmune chorea can result from various immunological mechanisms. Sydenham chorea (SC) is a classic example, but other immune-mediated causes could be a reasonable causative alternative. This chapter reviews the autoimmune causes of chorea, defining diagnostic criteria based on the clinical presentation, serological, and neuroimaging markers.