Screening mammography is a powerful tool for reducing breast cancer mortality. Mammography can often detect clinically occult, early-stage breast cancer that is amenable to successful treatment. However, mammography is not a perfect test and has lower sensitivity in young women and in those with dense breasts. Magnetic resonance imaging (MRI) has been shown to depict breast cancers that are occult to other forms of detection, including mammography. This has generated interest in the use of MRI for breast cancer screening. Although preliminary studies in highly selected populations show promise for the potential efficacy of breast cancer screening with MRI, there are many questions that should be addressed before this technique is offered to the general population.