Although contrast angiography is important in the diagnosis and treatment of atherosclerotic disease, it does have limitations. Intracoronary ultrasound more accurately assesses the amount of atherosclerosis and has given us new insights into the pathophysiology of coronary plaque accumulation and remodelling. It also allows the monitoring of therapeutic intervention. Intracoronary ultrasound is a new gold standard. It does not obviate the need for angiography but provides complementary information that enables us to perform optimal interventional procedures.