Whole heart coronary magnetic resonance angiography (MRA) has been established as a totally noninvasive diagnostic modality for the assessment of coronary artery disease. We report a case with unstable angina, in whom coronary artery stenosis with an atherosclerotic plaque was detected by whole heart coronary MRA. Intravascular ultrasound in the stenotic lesion revealed a soft plaque containing focal calcification, corresponding to a low-signal mass containing a no-signal mass on MRA. Whole heart coronary MRA can become a useful diagnostic tool for the diagnosis of acute coronary syndrome.