['Neutrophil/lymphocyte ratio (NLR) has been associated with poor outcomes in patients with cardiovascular diseases. However, little is known about the role of NLR in patients with thromboembolic stroke due to atrial fibrillation (AF). We aimed to compare the NLR ratios between non-valvular AF patients with or without thromboembolic stroke.', 'A total of 126 non-valvular AF patients with or without stroke were included in the study; 126 consecutive patients (52 males and 74 females), mean age, 70 ± 10.2 years old. No patient had a recent history of an acute infection or an inflammatory disease. Baseline NLR was measured by dividing neutrophil count to lymphocyte count. WBC count>12.000 cells per μL or <4.000 cells per μL and high body temperature>38 º are excluded from the study.', 'Mean NLR was significantly higher among persons with stroke compared to individuals without a stroke (5.6 ± 3.4 vs. 3.1 ± 2.1, p=0.001). There were no significant differences in RDW levels between the two groups (p>0.05). HAS-BLED and CHADS(2) scores were significantly higher in the stroke group.'] Is neutrophil/lymphocyte ratio associated with thromboembolic stroke in patients with non-valvular atrial fibrillation?