A 60-year-old man was admitted to our hospital due to acute ST-segment elevation myocardial infarction. He had a history of self-expanding stent implantation in the proximal left anterior descending artery due to stable angina pectoris 7 years earlier. Emergent coronary angiography on admission showed occlusion in the distal portion of the previously stented segment, in which observation by optical coherence tomography revealed the existence of a remarkable proliferation of lipid-laden neointimal tissues with rupture and thrombus. This suggests that very late stent thrombosis in a self-expanding stent may occur through the process of atheromatous formation.