Preliminary investigation into magnetic resonance (MR) imaging as a breast imaging technique has demonstrated several promising roles for this modality when used as an adjunct to mammography for the detection and diagnosis of breast cancer. There are many technical factors that must be considered, including high resolution, rapid imaging, fat suppression, and localization and biopsy capability. Potential clinical applications include differentiating benign from malignant lesions, detecting cancer when results of clinical examination or conventional imaging are equivocal, detecting cancer recurrence after breast conservation treatment, staging newly diagnosed breast cancer, and detecting occult cancer in patients presenting with axillary node metastasis. Pitfalls include false-positive and false-negative results. Awareness of the strengths and limitations of MR imaging of the breast will facilitate integration of this technique into the work-up of patients with suspicious breast lesions.