Cardiac resynchronization therapy (CRT) is a therapeutic option with proven efficacy in improving symptoms and reducing both hospitalization and mortality in patients with refractory heart failure. However, a significant number of patients do not respond to CRT and this may be due to incomplete or inappropriate selection and characterization of patients before pacemaker implant. Cardiac magnetic resonance imaging (CMRI) is an imaging technique that may assist cardiologists in this regard. This technique has the potential to improve the success rate of CRT, due to pre-interventional evaluation of left ventricular function, mechanical dyssynchrony, and characterization and quantification of scar tissue. Recently, venous coronary anatomy has also been successfully evaluated by CMRI. In this review the role of CMRI in patients with heart failure who are candidates for CRT is discussed and potential future developments are indicated.