Resistin is a recently described adipokine which is a member of cysteine-rich secretory protein family. Although it has been primarily defined in human adipocytes, it has been identified that its level was higher in mononuclear leukocytes, macrophages, spleen, and bone marrow cells. Because ankylosing spondylitis is an inflammatory disease, it is suspected that upregulation of proinflammatory cytokines is effective in its immunopathogenesis. The aim of our study is to determine the serum resistin levels in patients with AS and to research the relationship with disease activity markers. A total of 30 patients with AS and 30 healthy controls were included in this study. Serum resistin concentrations, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath AS Disease Activity Index (BASDAI) were evaluated. In results resistin levels in ankylosing spondylitis group were significantly higher than in control group. But, there was no correlation between resistin and ESR, CRP, BASDAI. In conclusion, higher serum resistin levels in patients with AS compared to healthy subjects give clues that resistin could have a role in the pathogenesis of AS.