Background: Omalizumab is useful as an add-on treatment in patients unresponsive to high doses of second-generation antihistamines. This study aimed to evaluate the efficacy and safety of omalizumab treatment in adolescents with refractory chronic spontaneous urticaria (CSU). Methods: CSU patients aged 12-18 years old with the diagnosis of symptomatic CSU and unresponsive to classical treatment were included in the study. All patients had an urticaria-activity-score (UAS7) of >= 16 or and were treated with 300 mg omalizumab every four weeks. The degree of response was classified into complete, partial and non-responders due to UAS7. Results: A total of 29 patients were evaluated. The median age and symptom onset age of the patients was 15.2 (IQR, 12.8-16.5) years and 14.0 (IQR, 11.8-15.9) years, respectively. The median duration of urticaria was eight (IQR, 4-24) months at admission. Eleven (37.9%) patients had angioedema and ten (34.5%) patients had concomitant allergic diseases. The median age at the beginning of treatment with omalizumab was 15.4 (IQR, 12.9-16.9) years. The median symptom duration was 12 (IQR, 6.5-27.5) months before the omalizumab treatment. Twenty-eight (96.5%) of the patients (89.6% complete, 6.9% partial) achieved response; however, one patient was a non-responder (3.5%). The adverse effect was observed in one (3.4%) patient as angioedema after the third dose. Twenty-three patients were followed up for a median of 18 (IQR, 13-27) months. Relapse was observed in three (13%) patients. Conclusions: Omalizumab is considered as an effective and safe treatment for CSU in adoles-cents. Relapses mostly occur within the first year after the cessation of treatment. (C) 2019 SEICAP. Published by Elsevier Espana, S.L.U. All rights reserved.