Patients with chronic heart failure might benefit from electrical therapy with a view to resynchronize the heart and improve its mechanical performance by cardiac resynchronization therapy (CRT) or to prevent the risk of sudden death by automatic defibrillation. These two therapies can be applied separately or with a combined device, the biventricular implantable cardioverter-defibrillator (CRT-D). There is currently no strong scientific evidence indicating that a CRT-D must be offered to all candidates for CRT. Plain common sense should limit the prescription of these costly devices for patients in need of secondary prevention or for younger patients without major comorbidities. The preferential choice of CRT pacemakers in the remainder of patients is currently a logical one.