A 55-year-old man was hospitalized for examination of a descending aortic aneurysm found on chest X-ray film. Aortogram and magnetic resonance imaging showed elongation and kinking of the arch and proximal descending aorta, which is associated with a descending aneurysm. A slit-like area of stenosis was found at the beginning of the aneurysm, but there was no pressure gradient across the stenotic lesion. The diagnosis of pseudocoarctation with aneurysm was done, and an operation was undertaken. The aneurysm and the kinking distal to the left subclavian artery were resected, and an artificial graft was inserted using partial cardiopulmonary bypass. This case is the tenth of pseudocoarctation associated with aneurysm reported in Japan.