Objective. To evaluate the diagnostic value of low-dose 256-slice CT angiography (CTA), MR angiography (MRA), and three dimensional-digital subtraction angiography (3D-DSA) in cerebral aneurysms. Methods. CTA, MRA, and 3D-DSA were performed in all enrolled patients to explore the diagnostic significance of the three different examinations. Results. There were 92 aneurysms confirmed during DSA and surgery in 79 patients. The diagnostic coincidence rates of DSA, CTA, and MRA were 96.7%, 89.1%, and 86%, respectively. The diagnostic coincidence rates of CTA and MRA were lower than those of DSA. The detection rate of CTA for aneurysms less than 3 mm in diameter was higher than that of MRA. Conclusion. CTA, DSA, and MRA have their own advantages and disadvantages in the diagnosis of cerebral aneurysms. They all have the diagnostic value for aneurysms.