Many noninvasive imaging methods for evaluating cardiac structure and function are available to cardiologists. MRI, however, is a newcomer on the scene and has not yet established a substantial niche in the day-to-day clinical management of patients or in providing data for basic and clinical research. The article explores the current and potential clinical and investigative applications of MRI and attempts to define the directions in which development should proceed to realize the full potential of this new methodology.