Etiopathogenesis of ankylosing spondylitis (AS), a major subtype of a group of chronic inflammatory diseases known as spondyloarthropathies, is not clearly understood yet. In this study, we aimed to investigate the interleukin 23 (IL-23)/interleukin-17 (IL-17) pathway, which is a new cytokine pathway in inflammatory diseases. We evaluated serum IL-17 and IL-23 levels after 1-year follow-up in AS patients using only nonsteroidal anti inflammatory drugs (at need or continue). Forty-four AS patients and 40 healthy controls were included in the study. Clinical evaluations of disease activity were performed. Serum tumor necrosis factor-α (TNF-α), IL-6, IL-17, and IL-23 levels were evaluated. IL-17 and IL-23 levels of the patient group at baseline and 12 months were lower than the control group. There was no significant difference between the baseline and 12th month evaluations of the patient group. TNF-α levels were similar in all groups (in the baseline and 12th month of the patient group and in the control group). Although our results are in contrast to the literature findings, the IL-23/IL-17 pathway is a newly discovered pathway, and there may still be unknowns. New studies involving larger patient groups are needed for the factors affecting serum IL-23/IL-17 levels in patients with AS. We also think that it will be useful to make more comprehensive and long-term studies about which patients will respond well to IL-23/IL-17 blockade.