Massive pulmonary artery aneurysms, while extremely rare, might require surgical intervention. Most previous cases have been repaired either by pulmonary artery plication or synthetic graft replacement. We report a case of massive pulmonary artery aneurysm that was successfully repaired using an ‘overlapping-plasty’ technique with the help of 3D image simulation. The ‘overlapping-plasty’ technique might support pressure resistance without the need for synthetic material. This specially designed procedure might be useful as a surgical option for pulmonary artery aneurysms.