The introduction of mammography screening has contributed to the increase in early-stage breast cancer detection rates up to 70.4%, thereby reducing standardized mortality rates by 14.5%. In this case, the detection rates at the earliest cancer stages, including in situ, increased, which made it possible to significantly expand the range of organ-sparing interventions and to increase the duration and quality of life in a woman. At the same time, due to the limited diagnostic abilities of mammography at a high radiographic density, there are still problems in detecting X-ray negative cancer, which lowers the effectiveness of screening. Objective — to increase the effectiveness of screening through the use of a complex of x-ray and ultrasound technologies in the detection and differential diagnosis of X-ray negative cancer. Subject and methods. Eighty-six women aged 24—77 years with X-ray negative, clinically occult diseases of different nature, which had been identified by ultrasound, were comprehensively examined. This study showed that the problem could be solved if the complex should include current ultrasound technologies, such as traditional ultrasound, Doppler energy (power) mode ultrasound angiography, radial duct sonography, compression sonoelastography, full-scale automated ultrasound scanning, as well as invasive technologies specifying the diagnosis, trepanobiopsy, and vacuum aspiration biopsy. Results. The pathological study of breast cancer revealed that invasive cancer prevailed (90.7%), the most common histological variant of X-ray negative cancer was invasive cancer without signs of specificity in 21 (65.6%) patients; the less common one was invasive lobular carcinoma in 8 (25%) patients. Non-invasive ductal carcinoma and non-invasive lobular carcinoma in situ were detected in 2 and 1 cases (9.3%), respectively. Benign changes were diagnosed in 54 (62.8%) cases: fibroadenoma in 32 (59.3%) patients; the less common lesions were proliferative fibrocystic mastopathy in 12 (22.2%) patients and fibrosis/fibrosclerosis, etc. in 5 (9.3%) patients. Conclusion. The elaborated differential diagnostic criteria for the co-use of X-ray echographic technologies increase diagnostic accuracy up to 95.3%.