Paraneoplastic neurological syndromes constitute a heterogenous group of diseases, which often cause severe neurological symptoms. Extensive research during the last 20 years has led to identification of new antigenic targets and inclusion of additional clinical conditions into this group of syndromes.The article is based on a non-systematic search of PubMed and the author's own experience with antibody analysis, treatment of patients and research within the field.Paraneoplastic neurological syndromes affect less than 1 % of all patients with cancer. The etiology is probably autoimmune, and involves immune responses (cellular and humoral) against antigens shared by tumor cells and normal neurons. Many, but not all patients harbour onconeural antibodies (in serum and spinal fluid), which are highly useful diagnostic markers for a paraneoplastic etiology. The cornerstone of therapy is treatment of the underlying tumor, but additional immunosuppressive therapy is often administered.