Objective: To determine Blood Eosinophilia frequency in newly diagnosed Chronic Obstructive Pulmonary Disease patients. Methods: An observational cross-sectional research on newly diagnosed COPD patients with age ≥ 40 years was performed at Ojha Institute of Chest Diseases, Dow University of Health Sciences Karachi. COPD patients diagnosed in outpatient clinic or admitted in Chest Unit during six-month period from September 2018 to May 2019 were selected. Each patient underwent spirometry, and blood was tested for eosinophilia (≥ 2% eosinophils in blood), after obtaining informed consent and clinical history. Results: One hundred and fifty COPD patients were diagnosed and evaluated for Blood Eosinophilia, out of which 86 (57.3%) and 64 (42.7%) patients were Males and Females respectively with mean age of 63.72 ± 10.24 years. Current Smokers were 48 (32.0%), Ex-Smokers 15 (10.0%), and Biomass Exposure was present in 76 (50.7%) of patients. Spirometric severity of COPD was Mild in 11 (7.3%), Moderate in 68 (45.3%), Severe in 59 (39.3%), and Very Severe in 12 (8.0%) patients. Blood Eosinophilia was present in 59 (39.3%) patients of COPD among which majority 43 (72.9%) were having Moderate 24 (40.7%) and Severe 19 (32.2%) COPD respectively. Conclusion: Frequency of Blood Eosinophilia in newly diagnosed COPD patients was high, among which most of the COPD patients were moderate to severe. doi: https://doi.org/10.12669/pjms.36.4.1624 How to cite this:Khan GM, Zuberi FF, Bizat-uz-Zahra S, Ghafoor L. Frequency of Blood Eosinophilia in newly diagnosed Chronic Obstructive Pulmonary Disease patients. Pak J Med Sci. 2020;36(4):---------. doi: https://doi.org/10.12669/pjms.36.4.1624 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.