Rebleeding of cerebral aneurysms has been previously reported during diagnostic angiography. However, capturing the exact moment of active rebleeding of a cerebral aneurysm during angiography is extremely rare. Here, a case of a rebleeding middle cerebral artery aneurysm during diagnostic digital subtraction angiography (DSA) was illustrated, accompanied with a video demonstration of the incident which is the only one in the literature. During the acquisition of lateral projection DSA images, active extravasation of the contrast medium was witnessed, indicating rebleeding. Simultaneously, there was a sudden rise in arterial blood pressure and an episode of bradycardia. The procedure was terminated immediately and the patient was transferred to the intensive care unit for extraventricular drainage and stabilization of vital signs. Unfortunately, the patient was lost.