The goal of this study was to determine whether a combination of shear wave elastography (SWE) quantitative parameters could improve the accuracy of ultrasonography in the differentiation of benign and malignant breast lesions. Two hundred seventy-nine breast lesions in 251 women were evaluated with ultrasonography and SWE; pathologic results of all lesions were available. Each lesion was classified according to the Breast Imaging Reporting and Data System (BI-RADS) for ultrasound. SWE quantitative parameters, including maximum elastic value (E-max), mean elastic value (E-mean), standard deviation (SD) and ratio of E-mean of the lesion to E-mean of the surrounding parenchyma (E-ratio), were recorded. A receiver operating characteristic curve was used to determine their cutoff values. When any of the four parameters was equal to or higher than the cutoff value, the set of SWE parameters was counted as positive. When both BI-RADS and the set were positive, lesions were evaluated as positive for malignancy. We compared the performance of this combination with use of BI-RADS, E-max, E-mean, SD or E-ratio alone and also with the combination of BI-RADS and E-max for benign/malignant differentiation. The combination of E-max, E-mean, SD, or E-ratio with BI-RADS had a sensitivity, specificity, positive predictive value, negative predictive value, accuracy and Youden index of 0.967, 0.912, 0.908, 0.969, 0.938 and 0.879, respectively. The accuracy was the highest (p < 0.01) without loss of sensitivity. Combining a set of SWE quantitative parameters (E-max, E-mean, SD and E-ratio) could improve the accuracy of ultrasonography in differentiation of benign from malignant breast lesions, without loss of sensitivity. (C) 2015 World Federation for Ultrasound in Medicine & Biology.