In 15 healthy volunteers undergoing coronary magnetic resonance (MR) angiography, the breath-hold duration with and without preoxygenation was measured. The effect of preoxygenation on coronary artery imaging was also evaluated. A three-dimensional magnetization-prepared true fast imaging with steady-state precession sequence was employed for coronary MR angiography. All subjects showed an increase in comfortable breath-hold duration with preoxygenation. This extra imaging time allowed coronary artery imaging with increased spatial resolution.