Objective: To prospectively evaluate the diagnostic value of 64-slice CTA in detecting intracranial aneurysms and to compare it with 2D-DSA and/or intra-operative findings.Material and Methods: 37 cases with SAH according to unenhanced cranial CT were included in the study. A 64-slice CTA was performed to all cases immediately after the nonenhanced cranial CT. DSA was performed in 24-48 hours following CTA. CT images were reviewed by two radiologists experienced in CT vascular imaging. The DSA reader was the angiographer who performed the DSA. The results of the CTA were compared with the DSA results and/or intraoperative findings in order to determine the diagnostic efficacy of CTA in detecting intracranial aneurysms. Results: Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CTA in detecting aneurysms were 92.8%, 83.3%, 96.2%, 71.4% and 91.2% respectively. The diagnostic value of CTA in detecting intracranial aneurysms was found to be equal to DSA by Mcnemar test. Conclusion: CTA is invaluable in detecting intracranial aneurysms. It may be used as a first line modality in SAH, and DSA may be reserved for patients with negative or equivocal CTA results.