Coronary pseudoaneurysms rarely occur spontaneously; rather, they are more commonly seen as a complication of coronary intervention. We present a case of a giant right coronary artery pseudoaneurysm with partial thrombosis after arterial perforation during percutaneous intervention for acute myocardial infarction and formation of a "daughter aneurysm" due to a contained rupture 12 years later. Right coronary pseudoaneurysm repair and coronary artery bypass grafting were eventually performed 16 years after the acute event. Cardiac magnetic resonance imaging, coronary computed tomography angiography, and autopsy findings are shown.