Background:Axial spondyloarthritis (axSpA) is a painful, inflammatory condition of the spine that usually manifests in young individuals with chronic back pain (less than 45 years of age). It may also be accompanied by extra-articular or periarticular (enthesitis, dactylitis) symptoms (uveitis, psoriasis, inflammatory bowel disease). AxSpA encompasses both ankylosing spondylitis (AS) with radiographic evidence of sacroiliitis and axSpA without radiographic evidence of sacroiliitis.Objective:to assess neutrophil/lymphocyte ratio (NLR) among AS patients and to evaluate its relation to disease activity. Methodology: The present investigation included thirty AS patients and thirty healthy controls. Disease Bath Ankylosing Spondylitis Disease Activity indicators were utilized to assess the disease activity of AS (BASDAI). Analyses were conducted on the relationship between NLR and disease activity.Results:There was a significant positive correlation between NLR and Duration of the disease (r=0.421, P=0.020), ESR (r=0.433, P=0.014), CRP (r=0.700, P< 0.001), BASDAI (r=0.433, P=0.017).There was an insignificant correlation between NLR and age. NLR had increased considerably among AS patients compared to controls (P-value <0.05).NLR can significantly predict AS disease activity (P-value <0.001, at cut off value ≥2.03 with 90% sensitivity, 88.89 % specificity, 94.7% PPV and 80% NPV).Conclusion:In conjunction with acute phase reactants, NLR might be a valuable marker for indicating inflammation.