Objective: Recently neutrophil-to-lymphocyte ratio (NLR) -the level of neutrophil reflecting the severity of inflammation and lymphocyte occurring after physiological stress has been gaining popularity, which was, along with other inflammatory markers, commonly accepted as an accurate marker of the inflammatory status. In this multi-centered study, an early, rapid, and low-cost diagnosis method was investigated. To this end, the correlation between chronic obstructive pulmonary disease and inflammation was planned to be utilized and whether neutrophil-to-lymphocyte ratio can be used as a valid tool in the diagnosis of acute exacerbations of chronic obstructive pulmonary disease was investigated. Method: We retrospectively enrolled the 467 patients. Control group included sex and age-matched healthy people. C-Reactive protein, forced expiratory volume-1, forced vital capacity, complete blood count and clinical data A receiver-operating characteristic curve analysis was performed to determine the best cut-off value of N/L ratio and C-Reaktif protein to predict the exacerbation. Two-sided p values <0.05 were considered statistically significant. Results: By spearman analysis, there was a strong correlation between. C-Reactive protein and N/L ratio in both stable group (r=0.436, p<0.001) and exacerbation group (r=0.534, p=0.001). Conclusion: Neutrophil/lymphocyte ratio may be a useful predictor of inflammation in chronic obstructive pulmonary disease and acute exacarbation of chronic obstructive pulmonary disease patients.