Cardiovascular magnetic resonance (CMR) imaging can provide a comprehensive assessment of cardiac morphology, structure and function. The guidelines for diagnosis and treatment of heart failure (HF) recommends a class I indication for CMR for the assessment of myocardial structure and function in patients with poor acoustic window. Due to its tissue characterization capacities CMR contributes to the etiological diagnosis of HF, discriminating among ischaemic and non-ischaemic causes of systolic dysfunction. Late Gadolinium enhancement (LGE) imaging can accurately quantify the extent and localize replacement fibrosis in LV walls. In this regard, CMR contributes to a better selection of patients for cardiac resynchronization therapy (CRTCardiac resynchronisation therapy (CRT)) and internal cardiac defibrillator (ICDInternal cardiac defibrillator (ICD)) implantation for primary prevention of sudden cardiac death (SCD). In the context of cardiomyopathies, CMR provides important information, for phenotype characterization, therapy selection and prognostication.