Background: Acute respiratory distress syndrome (ARDS) is a common clinical syndrome of acute respiratory failure as a result of diffuse lung inflammation and oedema manifested by hypoxemia and stiffness in the lungs. Cardiogenic pulmonary oedema (CPE) occurs when the oedema is secondary to acute cardiac failure. This study aimed to determine the predictive value of chest ultrasonography to differentiate between acute CPE and ARDS and in patients admitted to ICU with acute dyspnea to allow proper management in both cardiac and non-cardiac one. Methods: This cross-sectional study included 60 patients divided to two equal groups: Group I: included ARDS patients and group II: included CPE patients. All studied cases underwent clinical examination, laboratory investigations, echocardiography and chest ultrasonography. Results: we found 100% sensitivity of abnormal pleural lines and 96.7% of absent lung sliding in prediction of ARDS, also spared lines showed high sensitivity of 93.3% and 100% specificity. The presence of consolidation also showed a high accuracy of 86.6% while that for effusion was 40%. Abnormal pleural lines, absent lung sliding, and spared lines had no role in prediction of CPE, LOW sensitivity and specificity of consolidation, presence of pleural effusion showed a higher accuracy of 60%. Conclusion: chest ultrasonography can provide valuable information for differentiating between ARDS and CPE in patients presenting with acute respiratory failure. The presence of abnormal pleural lines, absent lung sliding, spared areas, and consolidations are highly suggestive of ARDS, while their absence combined with the presence of pleural effusion is more indicative of CPE.