A 46-year-old man underwent coronary angiography for stable angina. He developed inferior ST-segment myocardial infarction during the angiography. Intravascular ultrasound (IVUS) findings suggested coronary vasospasm. Intracoronary administration of isosorbide dinitrate restored the coronary flow. This case illustrates the essential role IVUS imaging played in establishing the diagnosis of catheter-induced coronary vasospasm.