May–Thurner syndrome is a rare clinical entity involving venous obstruction of the left lower extremity. The May–Thurner syndrome is a phenomenon commonly described as an acquired stenosis of the left common iliac vein secondary to compression of the left common iliac vein between the right common iliac artery and the underlying vertebral body. We report one case of May–Thurner syndrome, and another rare case of reverse May–Thurner syndrome, incidently detected during intervention, in a case of aortic stenosis and mitral stenosis with dextrocardia and situs inversus.