Optical Coherence Tomography (OCT) is a novel imaging modality, analogous to Intravascular Ultrasound (IVUS),but using light instead of sound.Like IVUS nearly 2 decades ago, OCT is now is radically changing the way we see coronary pathophysiology.OCT gives us a better understanding of in vivo vascular biology, and the influences of medical therapy and coronary intervention.The detail with which coronary pathophysiology is being viewed is unprecedented, such that we are only now just beginning to establish how this novel information might be best used to guide management, and influence patient outcomes.This presentation therefore describes the current status of intracoronary imaging with OCT, in what is already a rapidly evolving and dynamic field, and attempts to provide guidelines and indications for future clinical use.