The aim of our study is to determine the serum visfatin levels of patients with Behcet's disease and to investigate the relationship between visfatin, an adipokine released from adipose tissue, levels and activity of Behcet's disease. Fifty-eight patients with Behcet's disease were enrolled to the study. Nineteen of the patients were inactive, and 39 of them were active. We enrolled 30 healthy subjects as being control group. Visfatin and tumor necrosis factor alpha (TNF-alpha) levels were measured with ELISA method. Visfatin levels were significantly lower in patients with Behcet's disease whose illnesses were active or inactive than the control group (p<0.05). There was no significant difference between the active patient and inactive patient group. The reason for the lower levels of serum visfatin in active and inactive patients' group could be due to pro-inflammatory cytokines such as TNF-alpha and IL-6 which suppress genetic expression of visfatin in patients with Behcet's disease, or else.