Background/Purpose: The application of the checkbox for identifying patients with traits of both chronic obstructive pulmonary disease (COPD) and asthma proposed by the 2015 Global Initiative for Asthma (GINA)/Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations has not been well studied although such identification is important in clinical practice. Thus, we aimed to investigate the prevalence and features of COPD coexistent with asthma traits diagnosed based on the 2015 GINA/GOLD strategies, and explore the gap between guidelines and routine practice in the diagnosis and pharmacological management of such condition in a COPD cohort. Methods: COPD subjects were enrolled retrospectively throughout Taiwan. A patient record form was completed for each participant and the data were analyzed. Results: Of 340 participants, the prevalence of COPD coexistent with traits of asthma was 39.4% and 30.3% based on guidelines and physician's judgment, respectively. Coexistent patients were characterized by blood eosinophilia, higher total immunoglobulin E (IgE) levels, preserved lung function, and the presence of gastro-esophageal reflux disease and atopic disease while total IgE level > 100 kU/L and the presence of atopic disease were predictors for coexistent patients. Gaps existed in the diagnosis (a weak agreement with kappa = 0.53) and treatment (non-adherence to the preferred therapy in 18.4% of physician-judged coexistent patients) in COPD patients with asthma traits. The exacerbation history was similar between coexistent and non-coexistent patients. Conclusion: We found that measuring circulatory eosinophil and total IgE levels may raise clinicians’ awareness of the presence of traits of asthma in the management of COPD.