A 76-year-old man with effort angina was admitted to our cardiology department for an elective coronary angiography (CA). Diagnostic CA revealed severely calcified three-vessel coronary artery disease (CAD) with chronic total occlusions (CTO) of the right dominant coronary artery (RCA) and left circumflex artery (LCX), and severe calcific stenosis of the left descending artery (LAD). An urgent percutaneous coronary intervention (PCI) to treat the LAD was carried out because of ECG modifications and chest pain immediately after CA. During the procedure a septal collateral perforation occurred leading to abrupt development of a large intraventricular septal hematoma (IVSH). Urgent embolization of the culprit vessel with coils was performed using block and deliver (BAD) technique. Rapid hematoma expansion involved another proximal septal collateral. A prompt second coil embolization was carried out arresting the growth of the septal hematoma. The patient was discharged in stable condition and complete resolution of IVSH was confirmed by transthoracic echocardiogram two months later. Timely management of the septal perforation and close echocardiographic monitoring resulted in complete hematoma resolution and a satisfactory outcome.