Summary Despite developments in coronary interventional cardiology, plaque calcification is a critical issue of stent expansion. AngioSculpt Scoring Balloon Catheter® (AngioSculpt; AngioScore Inc., Fremont, CA, USA) can produce more ‘scoring’ marks, which leads to prevention of ‘plaque shift’ and ‘balloon slippage’; moreover, the ‘scoring’ produces some cutting effect, leading to successful stent implantation even on severe calcified lesions. We have applied AngioSculpt on severe calcified lesions to achieve its adequate expansion, and report the mechanism of the ‘scoring’ and its efficacy evaluated by three-dimensional stereoscopic reconstruction (3-D) of optical coherence tomography (OCT; LightLab Imaging, Inc., Westford, MA, USA). The patient is a 64-year-old male, who had diffuse stenosis in the left circumflex coronary artery (LCX) with severe calcifications, and was treated using AngioSculpt. AngioSculpt predilatation with a high pressure led to successful stent implantation. The radial scores were clearly imaged by 3-D OCT, demonstrating that radial nitinol wires made spiral indents from the relative weak points at the surface adjacent to calcification, which resulted in a less traumatic and safe dilatation although the scoring mark was not recognized clearly in intravascular ultrasound. This report suggests AngioSculpt might become one of the options for a severe calcified lesion.