The disorders of the central nervous system associated with cancer by remote immune-mediated mechanisms are a heterogeneous group. These disorders encompass the classic paraneoplastic disorders and the recently recognized autoimmune encephalitis associated with antibodies against neuronal cell surface or synaptic proteins that occur with or without cancer association. In the last decade, the new surge of interest in neuronal diseases associated with anti-neuronal antibodies led to the rapid discovery of new forms of disease that have different manifestations and were not previously suspected to be immune mediated. The recognition of these syndromes is important because it may lead to early detection of an underlying malignancy and prompt initiation of treatment, improving chances for a better outcome.