Objective: To evaluate the performance of lung ultrasound (LUS) in diagnosis of pulmonary congestion in patients with acute decompensated heart failure (ADHF). Missed or delayed diagnosis of patients with ADHF is associated with poor outcome. Lung Ultrasound has been demonstrated to be a valid tool for the assessment of pulmonary congestion through the quantification of the B-lines. The use of LUS to properly diagnose pulmonary congestion may provide early recognition of acute heart failure and the consequent early appropriate treatment. Methods: A total of 200 eligible patients with a diagnosis of ADHF who met the inclusion criteria were enrolled. They were diagnosed based on clinical (i.e. oxygen saturation (SO2)) and radiological (i.e. chest x-ray score) congestion parameters. Lung ultrasound was done on admission, after 24h and after 48h post admission. Lung ultrasound score was then correlated with other variables of congestion. Results: Lung ultrasound score showed correlations with other variables of congestion during the first 48h of admission. Conclusion: Lung US is a reliable tool for diagnosis of pulmonary congestion. The integration of lung US with the current diagnostic methods may have the potential to accelerate and improve the accuracy of ADHF diagnosis.