Screening mammography in women aged 40-49 years reduces breast cancer mortality by 16%-18%, and is recommended by various national organizations. However, one must be aware of the recognized limitations of the approach. The actual benefit appears to be small (absolute risk reduction, 0.07%; the number of women who need to be screened to prevent 1 woman from dying of breast cancer, about 1,500-2,500), and there are associated risks and costs with this approach. The medical and scientific communities, in partnership with advocacy groups, must continue to work to improve our breast diagnostic capabilities, especially in younger women. Since this is an emotional and controversial issue, each woman will need to consider, with the aid of her primary caregiver, whether the risks of screening outweigh its potential benefits, and make an informed decision regarding screening.