OBJECTIVE: In bronchiectasis cases, isolation of the bacterial infection agent is related with disease severity. The purpose of the study was to find the impact of bacterial infections on the prognosis of bronchiectasis exacerbations in patients hospitalized in the Intensive Care Unit (ICU). MATERIALS AND METHODS: A retrospective, single-center, clinical study was performed on 48 patients who were diagnosed as having bronchiectasis exacerbation in the ICU. Sputum cultures of the patients were collected at the time of ICU admission. Clinical characteristics, treatment with noninvasive ventilation, IV requirement, and mortality were recorded. RESULTS: The bacteriologic sputum examination was positive in 24 patients. The bacteriologic analysis of sputum cultures revealed Pseudomonas aeruginosa in 12 patients, Streptococcus pneumoniae in 4, Haemophilus influenzae in 3, Acinetobacter baumannii in 3, and Escherichia coli in 2 patients. Seventeen patients needed IV during ICU follow-up, 7 of whom died. Bacterial proliferation in sputum culture was correlated to IV treatment need (P = 0.005). The radiologic disease extent was greater in patients with culture proliferation (P = 0.028). The patients who needed IV treatment had a greater radiologic disease extent (P = 0.007), pulmonary artery systolic pressure pulmonary arterial pressure (PAP) (P = 0.004), C-reactive protein (P = 0.014), and number of hospital admissions (P = 0.017). A multiple regression analysis for treatment success involving the variables of PAP, culture results, and radiologic disease extent revealed that bacterial proliferation was the most important factor for treatment success (odds ratio: 2.05; confidential interval: [0.87–3.23]; P = 0.04). CONCLUSION: Positive bacterial examination of sputum is the most important prognostic factor for patients with bronchiectasis exacerbation admitted to the ICU.