Transcatheter aortic valve replacement (TAVR) is an alternative treatment option for patients with severe aortic stenosis. Although rarely described, mitral valve perforation because of mechanical stimulation due to low deployment of the prosthesis and the association with infective endocarditis, are potentially life-threatening complications that physicians should be aware of because patients should not be suitable for further surgical or percutaneous management. Herein, we present a case of an 88-year-old man presenting with worsening heart failure 6 months after TAVR. We discuss the diagnostic process and the therapeutic issues. Finally, we underline the invaluable role of echocardiography during TAVR procedures, due to its ability in detecting early complications and avoiding incorrect prosthetic deployment.