Film-screen x-ray mammography is an effective tool for the detection and diagnosis of breast cancer. Several limitations of current mammographic technology have been identified, and there is now good evidence that improved image quality and possibly reduced radiation dose could be achieved if mammograms are acquired directly in digital form. In this article, the rationale for digital mammography is presented and various approaches to the design of a digital mammography system are described. Current challenges in developing a practical, clinically acceptable digital mammography system are discussed and applications of digital mammography to computer-aided diagnosis, telemammography, and quantitative imaging are suggested.