SUMMARY Objective: To evaluate the diagnostic value of suspected malignancy signs on breast ultrasound. Methods : patients who have the solid mass in breasts underwent ultrasound examination (they have at least one of eight signs of suspected malignancy on breast ultrasound) and performed the ultrasound guided needle biopsy of these mass at Bach Mai Hospital from July 2019 to July 2020 were investigated. Results: 268 patients have breast tumors with signs of suspected malignancy detected on ultrasound (mean age, 42,1 years; range, 12 to 75). There were 97 breast cancer patients accounted for 36,2 %, including 84.5% of patients over 40 years old. Cancer lesions are mainly at the upper - outer quadrant position, accounting for 58,8 %. The sensitivity, specificity, PPV and the OR value in regression analysis of suspected malignancies signs, respectively: spiculation and/or thick hyperechoic halo ( 67,01%; 97,07%, 92,87%; 67,44), irregular shape with angular margins (89,69% and 70,76%; 63,5%; 21,05), retrotumoral acoustic shadowing (18,56 % and 98,83 %; 90 %, 19,25), hypoechoic echo pattern (96.91% and 7.02%; 37.15%), orientation not parallel (includes round solid nodules with round shape) (57,73 % and 84.21%; 67,47 %; 7,29), duct changes - enlarged ducts within surrounding tissues (24,74 % and 95.91%; 77,42 %; 7,7), microlobulations (38,14 % and 90.06 %; 68,52 %; 5,59), microcalcifications within or outside a mass (49,48 % and 89,47 %; 72,73%; 8,33). Conclusion: The signs of suspected malignancy on breast ultrasound have high diagnostic value in diagnosing breast cancer, especially the signs of spiculation and/or thick hyperechoic halo, irregular shape with angular margins and retrotumoral acoustic shadowing. In which, spiculation and/or thick hyperechoic halo is the sign with the highest UTV diagnostic value, followed by a sign of irregular shape with angular margins and retrotumoral acoustic shadowing. Hypoechoic echo pattern sign have high Se but low Sp and PPV, have no meaning in the diagnosis of breast cancer.