Among Kawasaki disease patients with systemic artery aneurysms, the brachial and internal iliac arteries are the most commonly affected, and occlusions of both arteries are often found. However, the long-term fate of large common iliac artery aneurysms remains unknown, because their prevalence is very low. The long-term outcomes of common iliac artery aneurysms caused by Kawasaki disease in four patients (three females, one male) were investigated retrospectively based on their medical records and angiograms. Their ages ranged from 30 to 36 years-old. The onset age of Kawasaki disease ranged from 4 to 8 months, and the interval from the onset of Kawasaki disease to the latest angiogram ranged from 17 to 21 years. All patients had bilateral large coronary aneurysms and common iliac artery aneurysms with maximal diameters greater than 10 mm. Although all patients had multi-vessel coronary artery stenotic lesions and systemic artery aneurysms, they were asymptomatic. The three female patients underwent coronary artery bypass grafting, and the male patient underwent replacement of artificial vessels for large bilateral common iliac artery aneurysms at 3 years old of age. Over the long-term, common iliac artery aneurysms greater than 10 mm persisted as calcified aneurysms. However, they had no symptoms due to their common iliac artery aneurysms, and their ankle brachial pressure index was preserved, even if the stenosis of the common iliac artery developed as a late outcome, because the collateral arteries were well developed. The progression of stenosis of the common iliac artery after Kawasaki disease was slower.