Biomarkers of clinical relevance are very important in the workup of patients presenting with neurological autoimmune diseases. Nervous biopsy remains often the "gold standard procedure" but is limited in practice due to the risk of complication and insufficient yield. These biomarkers, most often auto-antibodies, can be the direct cause of the neurological syndrome or be detected as an epiphenomenon of the pathogenic process. The detection of these biomarkers, when performed in well defined clinical conditions, may help the clinician to establish a definite diagnosis which may in turn facilitate the therapeutic decision. The purpose of this article is to review the biomarkers that are available in daily practice to investigate immune-mediated neurological conditions.