This study investigated phototherapy-induced changes in certain adipokine levels in patients with psoriasis. Patients with psoriasis (n=36) were recruited and body mass index (BMI) and disease severity (Psoriasis Area and Severity Index) were recorded. Serum resistin and leptin levels before and after bath-psoralen and ultraviolet (UV) A or narrow-band UVB therapy were examined by enzyme-linked immunosorbent assay. Serum leptin levels correlated positively with BMI. Phototherapy induced no remarkable change in the leptin levels, but significantly decreased serum resistin levels from 9.02±8.83 to 4.86±3.30 ng/ml. Serum resistin levels might be involved in insulin resistance and inflammation, and correlate with disease severity in patients with psoriasis. The reduction in serum resistin induced by phototherapy might be related to the clinical efficacy of this treatment for psoriasis.