<b><i>Background:</i></b> Knowing the cost of hospitalizations for exacerbation in bronchiectasis patients is essential to perform cost-effectiveness studies of treatments that aim to reduce exacerbations in these patients. <b><i>Objectives:</i></b> To find out the mean cost of hospitalizations due to exacerbations in bronchiectasis patients, and to identify factors associated with higher costs. <b><i>Methods:</i></b> Prospective, observational, multicenter study in adult bronchiectasis patients hospitalized due to exacerbation. All expenses from the patients’ arrival at hospital to their discharge were calculated: diagnostic tests, treatments, transferals, home hospitalization, admission to convalescence centers, and hospitals’ structural costs for each patient (each hospital’s tariff for emergencies and 70% of the price of a bed for each day in a hospital ward). <b><i>Results:</i></b> A total of 222 patients (52.7% men, mean age 71.8 years) admitted to 29 hospitals were included. Adding together all the expenses, the mean cost of the hospitalization was EUR 5,284.7, most of which correspond to the hospital ward (86.9%), and particularly to the hospitals’ structural costs. The adjusted multivariate analysis showed that chronic bronchial infection by <i>Pseudomonas aeruginosa</i>, days spent in the hospital, and completing the treatment with home hospitalization were factors independently associated with a higher overall cost of the hospitalization. <b><i>Conclusions:</i></b> The mean cost of a hospitalization due to bronchiectasis exacerbation obtained from the individual data of each episode is higher than the cost per process calculated by the health authorities. The most determining factor of a higher cost is chronic bronchial infection due to <i>P. aeruginosa</i>, which leads to a longer hospital stay and the use of home hospitalization