Autoimmunity has been demonstrated in a diverse range of peripheral neurological disorders, such as myasthenia gravis and acquired neuromyotonia. Serum antibodies found in these conditions are directed against ion channels and receptors situated on the cell surface and have been shown to produce pathogenic effects. The symptoms of these peripheral disorders have been transferred to animals by passive or active immunisation and, in humans, treated successfully with immunomodulatory therapy. Recently, a number of central nervous system disorders (CNS), such as limbic encephalitis, certain forms of epilepsy, neuromyelitis optica and cerebellar ataxia, have been hypothesised to associate with specific serum autoantibodies. In this article we consider this rapidly expanding field of CNS disorders, discuss evidence for their proposed autoimmune aetiology and review whether the antibodies detected have been shown to be pathogenic or if they are secondary to preceding neuronal damage.