A man with subacute sensory neuronopathy (SSN) had a stage 1 seminoma. His serum and cerebrospinal fluid (CSF) contained anti-Hu antibodies (type 1 anti-neuronal nuclear antibodies, ANNA-I). Following orchidectomy, radiotherapy, prednisolone, plasma exchange and intravenous immunoglobulin the antineuronal antibody titre fell and the neuropathy improved.