Magnetic resonance imaging (MRI) of the breast is now recognized as an effective modality in evaluating specific groups of patients with breast lesions or breast cancer and patients suspected of having hereditary BRCA1/BRCA2 mutations. Sensitivity of MRI in detecting breast cancer is high (88%-100%) and exceeds that of mammography and ultrasonography in detecting lesions in patients with occult disease. The specific applications of breast MRI range from detecting tumors in women with breast implants to monitoring response to neoadjuvant chemotherapy. In addition, a growing number of institutions are offering MRI-guided biopsy. Still, breast MRI is not a substitute for routine screening mammography, and results need to be interpreted carefully in conjunction with mammography and ultrasonography.