During the last two decades, tremendous advances have been made in the performance and interpretation of breast magnetic resonance imaging (MRI) examinations. Technical requirements for optimal breast imaging including the requirement for a breast MRI biopsy system are now being defined as part of a voluntary American College of Radiology (ACR) breast MRI accreditation program. The ACR BI-RADS (Breast Imaging Reporting and Data System) lexicon for breast MRI has brought uniformity to the interpretation of breast MRI examinations. With these advances in imaging technique, interpretation guidelines, and increasing availability of MR-compatible breast biopsy systems, MRI of the breast is rapidly gaining popularity in clinical practice in both the diagnostic setting and, more recently, in the screening setting. The clinical indications for breast MRI, however, remain to be defined. There are clinical indications that have emerged where MRI, as an adjunct to mammography, seems to be the imaging study of choice. There are other indications, specifically breast cancer staging, in which MRI is being utilized with increasing frequency, but in which controversy persists.