Nearly 10 years of experience in the use of MR imaging for the diagnosis of congenital heart disease has accumulated. Although MR imaging is superior to other techniques in showing certain structures and abnormalities such as small central pulmonary arteries in tetralogy of Fallot, aortic coarctations, and venous connections in heterotaxia syndromes, it remains an ancillary tool to echocardiography and cardiac catheterization. In this review, we examine present limitations and advantages of conventional MR in the evaluation of congenital anomalies of the heart and great vessels and explore future developments that might bring MR imaging into the diagnostic mainstream. Key improvements now in development are ultrafast MR systems for acquisition of multiple real-time MR images (in 30 msec or less) and on-line three-dimensional computer reconstruction of the heart and great vessels. Improved display and understanding of complex anatomy, as well as more extensive functional analysis of hearts before and after surgery, should be the benefits of such developments.