Introduction: Acute abdomen is a common presenting complaint in the emergency department, requiring prompt diagnosis and treatment. Clinical examination and ultrasonography (US) are commonly used diagnostic tools in the evaluation of acute abdomen. This study aimed to evaluate and compare the diagnostic accuracy of clinical examination and US in the diagnosis of acute abdomen. Methods: This was a prospective study that included 100 patients with acute abdomen who underwent both clinical examination and US. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of clinical examination and US were calculated. Additionally, the diagnostic value of US in the identification of different causes of acute abdomen was evaluated. Results: The overall sensitivity and specificity of clinical examination were 75% and 60%, respectively, while those of US were 85% and 70%, respectively. The PPV and NPV of clinical examination were 65% and 70%, respectively, while those of US were 75% and 80%, respectively. The accuracy of clinical examination and US was 67.5% and 77.5%, respectively. US was found to be more accurate than clinical examination in diagnosing acute abdomen. Conclusion: US is a valuable diagnostic tool in the identification of different causes of acute abdomen, with higher sensitivity and specificity compared to clinical examination. The diagnostic accuracy of US varies depending on the underlying cause of acute abdomen. These findings support the use of US as a first-line diagnostic tool in the evaluation of acute abdomen.