The common causes of organic mitral regurgitation (MR) include mitral valve prolapse (MVP) syndrome, rheumatic heart disease, and endocarditis. MR also occurs secondary to dilated cardiomyopathy and coronary artery disease. In acute severe MR, the hemodynamic overload often cannot be tolerated, and mitral valve repair or replacement must be performed immediately. We report herein a case of severe MR due to coronary vasospasm that was confirmed via ergonovine echocardiography in a 70-year-old man. He was scheduled to undergo mitral valve surgery, but it did not push through and he was put on medical therapy.