COPD is a growing cause of morbidity and mortality worldwide, and will be the third leading cause of death by 2020. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recently defined COPD as "Chronic Obstructive Pulmonary Disease (COPD) is a common, preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles or gases". [1] Hyperglycaemia is of interest as it is associated with poor outcomes from acute hospital admission for other conditions. Hyperglycemia associated with critical illness (also called stress hyperglycemia or stress diabetes) is a consequence of many factors, including increased cortisol, catecholamines, glucagon, growth hormone, gluconeogenesis, and glycogenolysis. Insulin resistance may also be a contributing factor. Acute hyperglycaemia is associated with poor outcomes from a wide range of acute illnesses including myocardial infarction, [2] stroke, [3] trauma and pneumonia [4]. Hyperglycaemia is thus associated with a poor outcome from a wide range of acute illnesses. However, the relationship between blood glucose levels and clinical outcomes in AECOPD has not been fully studied. The present study was undertaken to determine the relationship between blood glucose concentrations, HBA1c levels and clinical outcomes in patients of AECOPD.