Chronic idiopathic urticaria is defined as recurrent hives occurring for at least 6 weeks. In the majority of cases, there is no identifiable underlying etiology despite extensive evaluation. A subset of these patients is classified as having autoimmune urticaria defined by the presence of a functional IgG antibody to the α subunit of the high-affinity IgE receptor (FceRIa) or to IgE. The aim of this study was to evaluate the effects of the drug atorvastatin in patients with chronic urticaria compared to the placebo.In this single-blind study, 50 patients suffering from chronic urticaria (15-45 years old) were selected and divided into two groups by simple randomization method. The first group was treated with atorvastatin and antihistamines and the second group (control group) was treated with placebo and antihistamines for 3 months. Urticaria severity was measured by score index, before and after the treatment course: ASST (autologous serum skin test) was performed for all patients and sera were collected to measure cytokines. In cases, IL-5 decreased and IL-10 increased after treatment compared to the time point before treatment (p<0.05). All patients with severe utricaria according our scoring, had positive ASST.The patients with severe urticaria identified by urticaria score and ASST positivity had chronic idiopathic urticaria. By prescribing the atorvastatin plus antihistamines in severe and resistant forms of urticaria, the use of more toxic medications like cytotoxic drugs may be avoided.