Patients with autoimmune urticaria (AIU) and positive autologous serum skin test (ASST) represent a more serious type of chronic urticaria that does not respond to treatment with antihistamines, but responds completely to systemic corticosteroids. Because of the chronic course of the disease, there is a risk of side-effects. Cyclosporin A (CsA) is an alternative treatment for patients with AIU. In order to determine the efficacy of CsA at the lowest possible dose in patients with chronic idiopathic urticaria and positive ASST, 30 patients were included in a 5-month study with a follow-up one year after the end of treatment. All patients had positive ASST before treatment and autoantibodies were present in 73%. Twenty- three patients completed the study and responded to low-dose CsA treatment. Three patients did not respond to a dose of 2.5 mg/kg CsA, and 4 patients dropped-out due to side-effects. After the first month of treatment, an improvement of 31% was noted, reaching 88% after the fifth month of treatment. The mean dose of CsA was 2.16 mg/kg for the first month and 0.55 mg/kg for the fifth month. Three to 6 months after the end of the study, the ASST was repeated and was negative in 78.3% of patients. At the one-year follow-up, 20 patients were symptom-free (87%) and 3 had relapsed (13%). CsA, even in low-doses, can be an effective and short-term treat- ment with minimum side-effects in patients with AIU.