Diagnosis and treatment of chronic urticaria (CU - Chronic Urticaria) is one of the most difficult issues in allergy practice. Studies on the etiopathogenesis of chronic urticaria suggest that environmental factors, immune, genetic and hormonal are involved in triggering and maintaining the reaction of hives. In practice, despite detailed diagnosis is usually not possible to determine the real cause of the disease. For this reason, the use of causal treatment for patients suffering from chronic urticaria is not possible and supportive treatment is often ineffective. 0.1% of the population suffers from chronic spontaneous urticaria, which main cause has not been detected. Very often CU coexists with autoimmune thyroid dysfunction. Studies confirm higher incidence of thyroid antibodies in patients with chronic urticaria than in the general population. We analyzed 100 patients who met the criteria for chronic urticaria according to the WHO, in Allergology Clinic of the University Hospital Jagiellonian University Medical College. According to our study 17.4% of patients with chronic spontaneous urticaria occurred elevated titer of anti-TPO antibodies. In patients with non-spontaneous type of CU, elevated titer of anti-TPO antibodies only occurred in 8.3% of patients, and this difference was statistically significant p = < 0.003. All the patients had thyroid levels normal and there were no clinical symptoms of thyroid dysfunction. Our research indicates a link with autoimmune thyroid diseases, especially Hashimoto's disease, with a prevalence of CU. It is necessary to conduct further studies to confirm the relationship of pathogenic autoimmune thyroid disorders with the occurrence of CU, which will help to provide the causal treatment of spontaneous CU coexisting with high levels of anti-TPO antibodies in patients with euthyroid status.