Objective: To investigate the usefulness of sonographic findings, including the internal echogenicity and associated changes in the pleura and lung parenchyma, in determining the nature of pleural effusion.Methodology: This study was conducted on 50 children between 2 months and 13 years old with clinically suspected pleural effusion. They were subjected to full history taking and clinical examination ,routine laboratory investigations as CBC,ESR, tuberculin test and sputum analysis, laboratory analysis of pleural aspirate, chest x ray, chest ultrasound and CT chest if needed .Results:we regarded transudates (50%) as usually anechoic. Exudates (29%) were considered when the PE was homogenously echogenic, complex septated and complex nonseptated. Chest ultrasound gave the same diagnosis as that given by Laboratory pleural aspirate analysis in 91% cases. Chest U/S was found to be more sensitive than CXR in the assessment of pleura and pleural fluid.Conclusion: Chest U/S is very valuable in assessing the nature of pleural effusion and its use should be considered in as a screening tool before going to the other invasive techniques. Cases with pleural effusion as detected by CXR should also be investigated with U/S to avoid unnecessary thoracothentesis and to act as useful guide for thoracothentisis if it’s going to be done.