Background: Accurate evaluation of pleural effusion is crucial for effective clinical management. This study aimed to compare the diagnostic value of high-resolution thoracic ultrasound with chest radiography in patients presenting with pleural effusion. Methods: A prospective observational study was conducted in the Radiology Department of Salah Al-Deen General Hospital from April 2022 to February 2023. A total of 23 patients diagnosed with pleural effusion were included, comprising 13 males and 10 females, with a mean age of 49 years (range: 14–74 years). All participants underwent detailed clinical, laboratory and radiological assessments. The diagnostic performance of thoracic ultrasound was compared with chest radiography in terms of accuracy and characterization of pleural effusion. Results: A statistically significant difference was observed between chest radiography and ultrasound in the evaluation of pleural effusion (p<0.001). Thoracic ultrasound demonstrated superior accuracy in assessing both the nature and extent of pleural effusion. The sensitivity of ultrasound was 78%, whereas chest radiography showed limited reliability, particularly in estimating the volume of effusion. Moreover, ultrasound was more effective in differentiating types of pleural effusion and detecting loculated collections. Conclusion: High-resolution thoracic ultrasound is a reliable, non-invasive and bedside imaging modality with greater diagnostic accuracy than chest radiography for evaluating pleural effusion. It also plays a pivotal role in guiding thoracentesis, ensuring safe chest tube placement and monitoring fluid drainage, especially in critically ill or mechanically ventilated patients.