This book constitutes the refereed proceedings of the 11th International Workshop on Digital Mammography, IWDM 2012, held in Philadelphia, PA, USA, in July 2012. The 42 revised full papers and 58 revised poster papers presented were carefully reviewed and selected from numerous initial submissions. The papers are organized in topical sections on contrast-enhancing imaging, digital mammography methods, tomosynthesis system design, tomosynthesis - image quality and dose, clinical tomosynthesis, functional breast imaging, breast computed tomography, computer-aided diagnosis and image processing, tomosynthesis reconstruction, and breast density.