Intravascular ultrasound (IVUS) is a clinically useful tool that provides cross-sectional images of the coronary arterial lumen and wall. Diagnostic applications of IVUS include the evaluation of ambiguous lesions on angiography particularly at the bifurcations. IVUS is also useful in the assessment of coronary vasculopathy in cardiac transplant patients or it can help to diagnose abnormalities such as syndrome X or coronary artery spasm. IVUS can optimize the performing of percutaneous coronary interventions, especially stent implantation. It represents as well an optimal tool for assessing regression of atherosclerosis. Three-dimensional reconstruction, elastography and imaging guide wires are some of the recent advances in the field of intravascular ultrasound.