Lipid core–containing coronary plaques (LCPs), which cause most acute coronary syndromes and complications related to percutaneous coronary intervention (PCI), cannot be detected with coronary angiography. A near-infrared spectroscopy (NIRS) catheter-based system has been developed for intracoronary detection of LCP. The system was validated ex vivo in an autopsy study and in vivo in the multicenter SPECTACL study. Anecdotal case reports are emerging that hint at the clinical utility of this device in patients with coronary artery disease undergoing PCI in terms of predicting no-reflow, periprocedural myocardial infarction, or determining optimal stent length. However, it is not known whether widespread use of this device will translate into clinical benefit, a question which will need to be investigated in future studies. In this article, we review the evolution of NIRS technology in detection of LCP and the future direction of this imaging modality in optimizing the results of PCI.