The cutting balloon is a device that enlarges atherosclerotic coronary arteries by a combination of plaque incision and dilation. This peculiar mechanism would account for a better immediate result achieved at the cost of minimal vessel wall trauma. Coronary perforation is however a potential complication. No systematic data have been reported as to which angiographic lesion characteristic may predict the occurrence of complications after cutting balloon angioplasty. This case report study deals with different types of coronary artery wall injury complicating cutting balloon angioplasty and detected by intravascular ultrasound.