Two cases of contrast media extravasation of a ruptured aneurysm during computed tomography angiography (CTA) are described. The contrast media extravasation appeared as a highly attenuated twisted ribbon-like structure originating from the aneurysmal dome, and this mimicked a vascular structure. Because rebleeding of an aneurysm is accompanied by disastrous consequences, it is important to understand the imaging feature of active bleeding on CTA.