Modern ultrasound examination (US), unlike other modalities, allows to assess the stiffness of the lesions, with the help of a new technology named sonoelastography (SEG). According to many scientific studies, with the addition of SEG to the B-mode, the diagnostic efficiency of ultrasound of breast lesions significantly increases. According to Thomas et al. B-mode has a sensitivity of 91,8% and a specificity of 78%. When a compression SEG is added to a diagnostic study, the specificity increases to 91,5%.The purpose of this study was to determine the diagnostic effectiveness of SEG and compare it with the effectiveness of B-mode and color Doppler mapping (CDC) in the primary diagnosis of breast tumors, as well as to identify diagnostically and statistically significant SEG signs of breast cancer (ВС).Materials and methods. The study was performed from 2017 to 2019 on the basis of the «NMRC Oncology. named after N. N. Petrov» Ministry of Health of Russia. 277 women with complaints of lump or pain in the breast were included in the study, for all of them there was performed the multiparametric ultrasound examination with application of CDM and SEG. According to our own results, SEG is more effective at detection of malignant and benign lesions, than ultrasoumd examination in B and CDM modes.Results: 0, 1, 2, 3 elastotypes are the highly significant diagnostic signs of benign process, and the elastotype 5 is a reliable diagnostic marker of malignant process. The effectiveness of CDM and SEG in the differential diagnosis of breast lesions showed: sensitivity - 77,6% vs. 85,5%; specificity - 51,7% vs. 84,6%; accuracy - 58,8% vs. 84,8%.Conclusions: according to our own research results, SEG is more effective in detecting malignant and benign tumors than ultrasound in B and CDM modes.