Heart failure is characterized by several abnormalities of sympathetic cardiac activity that can be assessed by 123I metaiodobenzylguanidine single photon emission computed tomography (MIBG SPECT). This technique may be useful in the clinical management of heart failure patients. Abnormal MIBG uptake has been demonstrated to be a predictor of death and arrhythmic events in heart failure patients with a prognostic power incremental to that of conventional risk markers; it may also be useful to identify patients at low risk of arrhythmias despite current guideline indications for an implantable cardioverter-defibrillator (ICD) or patients at high risk for arrhythmias not fulfilling ICD indications. This review will focus on the clinical applications of MIBG SPECT in chronic heart failure, on the basis of the most recent evidence.