A 85-year-old man suffering from unstable angina was scheduled to undergo coronary angiography. Medical history included previous myocardial surgical revascularization [performed in July 1995 with a left internal mammary artery (LIMA) graft implanted on left anterior descending (LAD) coronary artery] and percutaneous coronary intervention (PCI) with one stent implanted from protected left main (LM) shaft to proximal left circumflex (LCX) (performed in July 2019). Based on angina reappearance and positive stress test findings, a new invasive coronary angiography was planned. Angiographic assessment revealed a patent LIMA graft to the LAD and the presence of a significant ostial LM stenosis ( Fig. 1 A). Thus, the lesion was judged deserving of PCI. LCX ostium wiring (with a workhorse coronary wire) required several attempts due to significant friction. PCI of the ostial LM was performed with implantation of a short drug-eluting stent (Xience Pro A 3.50 × 8 mm - Abbott Vascular, Santa Clara, USA) ( Fig. 1 B). To provide evidence of optimal LM stenting result, intracoronary imaging was planned. An Optical Coherence Tomography (OCT) catheter (Dragonfly OPTIS, Abbott Vascular) could not be advanced across the LCX ostium, which was then dilated with 1.5 and 2.0 mm semi-complaint balloons to allow intracoronary imaging. Surprisingly, OCT images showed the presence of an intracoronary undeployed stent, located between the LM shaft and the proximal LCX ( Fig. 1 C to F and Online video ) and presumably lost during PCI performed in July 2019. Small thrombus appeared attached to the platform. The proximal edge of the lost device was “crushed” behind the presently implanted LM stent, a finding better appreciable in the 3-dimensional OCT reconstruction. In order to minimize the risk of intracoronary thrombosis, we dilated the coronary segment with a 3.0 mm non-compliant balloon, crushing the entire undeployed stent.