- Chronic obstructive pulmonary disease (COPD) is characterized by progressive exertional and resting dyspnea and is associated with major co-morbidities. Hemoglobin level disorders (anemia and polycythemia) prevalence among patients and the relationship between them and the clinical expression are still not characterized unequivocally. The main purpose of this work is to test the association between anemia and hospitalizations. The presence of such a link may promote the diagnosis and treatment aimed at the patient's hemoglobin levels. Anemia in patients with COPD is associated with an increased number of hospitalizations. A retrospective cohort study analysis, conducted on a group of COPD patients (n = 333) followed in the Pulmonology Institute of the Soroka University Medical Center in the years 2003-2009. Demographic physiological and clinical characteristics were compared between anemic, polycythemic and normal hemoglobin patients. Using statistical models, we examined the relationship between the presence of anemia and clinical outcome. Anemia was found in 79 patients (24%) and polycythemia among seven patients (2%). No difference was found between the groups in terms of number of hospitalizations, number of hospitalization days and ventilator events. There was a higher rate of co-morbidities (such as heart failure, chronic kidney disease) among anemic patients. There were also lower values of BMI and lung function and a higher proportion of men among anemic patients. Anemia in patients with COPD was not associated with an increase in the number of severe exacerbations. More studies are needed to clarify the threshold of a hemoglobin level below which there is an increase in the rate of hospitalizations.