A 20-year-old man with mental impairment, was referred to us for evaluation of recurring idiopathic urticaria episodes, characterized by a diffuse spreading of wheals and severe itching lacking response to traditional antihistamines. Upon physical examination, he showed a persistent, generalized, reticular, red-bluish vascular skin pattern in association with diffuse arborizing telangiectasias. Such lesions were present from an early age. Laboratory and instrumental tests, performed in order to exclude any condition associated with livedo did not evidence pathological results. He was found to be positive for antinuclear autoantibodies (ANA; 1:640). Histopathologically, numerous dilated capillary vessels associated with sparse extravasated erythrocytes were observed in the upper dermis. We performed an autologous serum skin test (ASST), which resulted in a positive, suggesting an autoimmune basis of the condition. On the basis of clinical and histopathological findings, and in the absence of other clinical and laboratory data suggesting other neoplastic, immunological or systemic diseases, the diagnosis of cutis marmorata telangiectatica congenita (CMTC) associated with chronic autoimmune urticaria (CAIU) was made. CMTC is a rare congenital vascular disorder, consisting in an anomalous, persistent, red-bluish marbling of the skin, that can be associated with a wide spectrum of cutaneous and extracutaneous anomalies. In our case, neither physical examination nor instrumental investigation demonstrated any of these anomalies, with the exception of cognitive impairment. We report this case because of the rarity of a diagnosis of CMTC in an adult patient, because this condition has almost always previously been diagnosed in infancy, or it comes to observation because of the presence of associated disorders, as in our case for chronic urticaria.