Neutrophil-lymphocyte ratio (NLR) has been associated with poor outcomes in patients with cardiovascular diseases. We aimed to compare NLRs among patients with nonvalvular atrial fibrillation (AF) with or without left atrial (LA) thrombus.A total of 309 (70.1 ± 9.8 years, 49% male) patients with nonvalvular AF have undergone transoesophageal echocardiography (TEE) to assess the presence of LA thrombus. Baseline NLR was measured by dividing neutrophil count to lymphocyte count.Left atrial thrombus was detected in 32 (10.3%) of 309 patients. Mean NLR (2.2 ± 1.0 vs 2.7 ± 1.1, P = .026) was significantly higher among patients with LA thrombus compared to patients without LA thrombus. On multivariate analysis, NLR (odds ratio 1.59, 95% confidence interval 0.87-4.18; P < .02) was an independent risk factor for the presence of LA thrombus in patients with nonvalvular AF.Neutrophil-lymphocyte ratio, an emerging marker of inflammation, was independently associated with the presence of LA thrombus in patients with nonvalvular AF.