Objective — to study breast cancer (BC) detection rates in women undergoing screening in the subjects of the Russian Federation (RF). Material and methods. The data available in Reporting Form No. 131 were used to conduct an analytical and statistical study of BC detection rates in women aged 39 years and older during screening in 2017. Results. In the whole RF, the rate of new-onset BC in women aged 39 years and older was 93.4 per 100.000 examinees. Screening revealed that BC is the most common form of malignant neoplasms (MNs) in women aged 39 years and older, especially in the older age group (60 years and older). Stage I—II BC was detected in 58% of all the cases of new-onset BC (n=8598). There were significant fluctuations in the rate of new-onset BC in different subjects of the RF from 11.3 to 172.1 per 100,000 examined women (p<0.05). In the subjects with lower BC mortality, the rate of new-onset Stages I—II BC was considerably higher than that in the subjects with higher mortality from this disease (105.7 and 37.0, respectively; p<0.05). Assessment of the diagnostic significance of mammography showed that 668 breast radiographies were carried out in the whole RF to identify one new case of BC. There were evident interregional fluctuations in this rate with a 2—15-fold difference. A correlation analysis of the number of breast radiographies per one new identified case of BC («effectiveness») and the rate of new-onset Stage I—II BC revealed a significant negative correlation (r =–0.57; p<0.001). Conclusion. To improve the performance of screening mammography used during preventive medical examination aimed at reducing mortality rates, special attention should be paid to the quality of mammography, including medical equipment and training of the staff assessing the results of examination during screening.