Paraneoplastic neurological syndrome (PNS) associated with anti-CV2/CRMP5 antibodies is a rare entity that can present in various clinical manifestations, from encephalitis to chorea, depending on the brain region involved. We report a case of an elderly person with small cell lung cancer who presented with PNS encephalitis associated with anti-CV2/CRMP5 antibodies which were confirmed on immunological analysis. This evidence concerns the gene DPYSL5 and small cell lung carcinoma.