Scientific background: Chronic inflammatory demyelinating polyneuropathy ( CIDP) is presumed to occur by autoimmune mechanisms. Its course is multifocal demyelination of the peripheral nerves. If the progress of clinical picture is longer than 2 months, CIDP must be considered. It often presents with symptoms that include weakness of the arms and legs, tingling or numbness, and spontaneous pain. Graves disease or in other words diffuse toxic goiter is one of the most frequent type of thyrotoxicosis in the population. It is an autoimmune disease caused by thyroid stimulating antibodies and immunoglobulins against TSH receptors. Graves disease's triad includes goiter, thyrotoxicosis and ophtalmopathy. In this paper; a case of comorbidity of these two autoimmune conditions is presented with additional referral to the literature. Case: 26 year-old woman presented with the complaints of tingling, numbness, pain and weakness of upper and lower extremities. She stated that tingling, numbness and weakness progressed in 3 months accompanied by mild pain. CIDP is considered according to the neurological examination, EMG findings, albuminocytologic dissociation in CSF, exclusion of the other PNP reasons and the history of clinical progression in 3 months.