Paraneoplastic sensitive neuropathy is one of the most common presentations among a group of cancer-related disorders known as Paraneoplastic Neurological Syndromes (PNS). PNS likely have an autoimmune etiology since they have been associated with the presence of antibodies against neuronal antigens expressed by tumor cells (such as anti-Hu, anti-Ri and anti-Yo). The tumors most frequently associated with PSN and onconeural antibodies are lung cancer, lymphomas and gynaecological tumors; however, they have also been described in other tumors. We report, for the first time, a case of neuroendocrine tumor of duodenum and PNS associated with anti-Hu antibodies. Moreover, we analyze and discuss the clinical implications that PNS and anti-Hu could have in patients with tumors.