BACKGROUND: The characteristics of plaque components according to aging process are not well known. OBJECTIVES: We assessed the age-related differences in pre-intervention virtual histology-intravascular ultrasound (VH-IVUS) findings at target lesion sites in patients with coronary artery disease. METHODS: A total of 553 patients who underwent pre-intervention VH-IVUS imaging were grouped according to age: non-elderly (���70 years, n=429) and elderly (> 70 years, n=124). VH-IVUS classified the color-coded tissue into four major components: fibrotic, fibro-fatty, dense calcium (DC), and necrotic core (NC). Thin-cap fibroatheroma (TCFA) was defined as focal, NC-rich (��� 10% of the cross-sectional area) plaques being in contact with the lumen in a plaque burden ��� 40%. RESULTS: Proximal and distal reference segment plaque burdens were significantly greater in elderly group (39짹8 mm2 vs. 37짹8 mm2, p=0.042, and 38짹7 mm2 vs. 36짹8 mm2, p=0.048, respectively). The absolute and percent areas of DC (0.67짹0.62 mm2 vs. 0.57짹0.57 mm2, p=0.032, 11.8짹10.9% vs. 9.9짹9.6%, p=0.039, respectively) and NC (1.29짹1.17 mm2 vs. 1.14짹0.97 mm2, p=0.014, 20.8짹11.8% vs. 18.1짹11.6%, p=0.023, respectively) at the minimum lumen site were significantly greater in elderly group. The absolute and percent volumes of DC (11.0짹11.0 mm3 vs. 9.7짹11.9 mm3, p=0.033, 11.7짹8.1% vs. 9.8짹7.2%, p=0.014, respectively) and NC (18.5짹17.6 mm3 vs. 16.6짹18.9 mm3, p=0.020, 18.8짹8.8% vs. 16.5짹9.3%, p=0.026, respectively) were significantly greater in elderly group. There was a trend towards higher incidence of TCFA in elderly group (65% vs. 56%, p=0.089). CONCLUSIONS: VH-IVUS analysis demonstrates that elderly patients have more NC and DC-containing plaques compared with younger patients. This may be associated with poorer outcome in elderly patients compared with younger patients.