Use of breast MRI in the preoperative evaluation of patients recently diagnosed with breast cancer has increased significantly over the past 10 years because of its well-documented high sensitivity for detecting otherwise occult breast cancer in the affected and contralateral breasts. However, published research reports on the impact of this improved cancer detection are limited. Equally important are growing concerns that the quality of breast MRI may vary significantly across practice sites, and therefore the published value of MRI may not be achieved for many patients. This article describes the peer-reviewed, published clinical research trials evaluating breast MRI in patients with newly diagnosed breast cancer on which the National Comprehensive Cancer Network (NCCN) practice guidelines are based. The current NCCN guidelines recommend that breast MRI be considered for patients with a newly diagnosed breast cancer to evaluate the extent of ipsilateral disease and to screen the contralateral breast, particularly for women at increased risk for mammographically occult disease. In addition, the guidelines indicate that breast MRI may be used for patients with axillary nodal adenocarcinoma to identify the primary malignancy. The guidelines stress the importance of having proper equipment, imaging technique, and provider training necessary to achieve high-quality breast MRI, and emphasize that MRI practice sites should have the ability to perform MRI-guided biopsy or needle localization. In addition to describing the data regarding use of breast MRI in women with newly diagnosed cancer, this article provides recommendations for the performance of high-quality breast MRI and suggestions for future research.