Magnetic resonance imaging (MRI) has become a useful, even essential, examination in recent years, for the exploration of patients with coronary disease. MRI has several different roles, even though it remains insufficiently requested because insufficiently available. Today it is the reference examination for assessing indicators of ventricular function (volume, ejection fraction, ventricular mass); their prognostic value and importance in determining treatment are well recognized. In the postinfarction period, MRI using late enhancement techniques allows a precise analysis of the extent of necrosis, in terms of segments and transmural involvement. MRI is indicated, especially preoperatively, in cases of ventricular remodeling and its consequences (functional impairment, aneurysms, parietal thrombus). MRI with pharmacological stress may also be used as a tool for detecting myocardial ischemia; in this case, perfusion or first-pass sequences should be used. On the other hand, cardiac MRI for morphologic exploration of the coronary network and measurement of stenosis is not yet routine.