There are many causes for cervical dystonia (CD), although most cases are idiopathic and a cause cannot be identified. The observation that 10-15% of cases have an affected family member has pointed to genetic causes, but known genes account for only a small fraction of all cases. The current manuscript describes a series of studies focusing on potential autoimmune or inflammatory mechanisms in CD. First, a case-control survey for 32 autoimmune diseases in 271 subjects with CD confirmed prior anecdotal observations that CD is associated with thyroid disease, which often results from autoimmune mechanisms. Second, unbiased proteomic methods involving a total of 20 subjects with CD, with or without associated thyroid disease, pointed towards a series of overlapping mechanisms relating to the immune system. Third, a multiplex immunoassay focusing on 37 markers associated with neuroinflammation applied to a total of 20 subjects with CD with or without thyroid disease and 20 controls pointed to abnormalities in several specific measures of the immune system. Finally, a broad screening test for neuronal antibodies in a total of 58 subjects with CD did not disclose any specific antibodies. Altogether, the association of CD with thyroid disease and blood-based immune measures point to abnormalities in cell-mediated immunity that may play a pathogenic role for a subgroup of subjects with CD.