A new technique for breast imaging is presented. This technique combines radiographic mammography directly with automated ultrasound. The combined examination, which is performed without decompression of the breast, yields the conventional mammography films as well as a complete set of B-mode scans and ultrasound projections. These can be geometrically matched with each other in a definitive manner. A prototype of the device was first used in a pilot study of 50 patients followed by a study of an additional 450 patients with a total of 492 breast lesions, of which 269 were confirmed by histology or cytology. The results show that X-ray and ultrasound are complementary in the detection of cancer. The use of an experimental mode of image interpretation for combined mammography and automated ultrasound reduced the number of mammographically suspicious findings that ultimately turned out to be benign. These results were also confirmed in two blind studies including a total of 160 histologically or cytologically confirmed lesions and 40 cases without lesions. With further technical advancement of the technique aimed at rapid and easy application and confirmation of the results obtained so far, the combination of mammography and automated ultrasound might be introduced into a routine clinical setting.