Diagnosis and assessment of coronary artery disease (CAD) is especially difficult in women. The history of chest discomfort and various noninvasive tests each have particular problems, which indicate the need to consider more accurate tests such as cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET). MRI of cardiac function at rest and during dobutamine stress has good accuracy, and MR Myocardial perfusion imaging (MPI) with gadolinium DTPA looks promising. The most exciting MR method is cineangiography (MRA), which images blood flow through the coronary arterial lumen as an intense signal. In an initial clinical trial this method showed excellent sensitivity and fair specificity in patients in whom adequate images could be obtained. MR spectroscopy (MRS) has imaged changes in high energy phosphates in patients with severe coronary stenoses during handgrip exercise, but is still experimental. PET MPI corrects the images for attenuation problems that limit the use of other radionuclide imaging procedures in women more than in men. Many studies show excellent sensitivity and specificity to diagnose CAD by PET MPI. In view of its clinical validation and the safety of dipyridamole relative to dobutamine, PET MPI appears to be the best test for assessing CAD in women. The greater accuracy of PET (or perhaps of fully developed MRI/MRA systems) will produce better clinical outcomes and cost-effectiveness for most patients than will less accurate modalities, despite their higher initial cost.