Background and Design: Interleukin-23 (IL-23) is a cytokine which is believed to have an important role in the pathogenesis of autoimmune diseases. Therefore, it can be used as a target molecule in the treatment of autoimmune diseases. The aim of our study was to determine serum IL-23 levels in patients with vitiligo to understand their possible roles in the disease etiology and to compare the results with the healthy controls. Materials and Methods: Fifty-one patients, who applied to the dermatology outpatient clinic and were diagnosed with vitiligo clinically and by wood lamp inspection, were enrolled in our study. Thirty-six age-and sex-matched healthy subjects were also enrolled as the control group. Serum IL-23 levels were studied in peripheral venous blood samples. Statistical analyses were made by SPSS version 16.0 for Windows . Results: Vitiligo group and control group were similar in terms of age and sex. Generalized type vitiligo was detected in 27 (52,9%), whereas focal, acrofacial, segmental and universal forms were detected in 13 (25,5%), 5 (9,8%), 3 (5,9%) and 3 (5,9%) of the patients, respectively. Mean serum IL-23 values were not significantly different between patient and control group (p=0.606). We also showed that serum IL-23 levels