Objectives-This pilot study evaluated use of contrast-enhanced ultrasound (CEUS) to reduce the number of benign breast masses recommended for biopsy.Methods-This prospective study included 131 consenting women, from October 2016 to June 2017, with American College of Radiology Breast Imaging Reporting and Data System category 4a, 4b, and 4c masses detected by mammography, conventional ultrasound (US), or both. Contrast-enhanced US examinations (using intravenous injection of perflutren lipid microspheres or sulfur hexafluoride lipid-type A microspheres) were performed before biopsy. Qualitative and quantitative CEUS parameters were compared with reference standard histopathologic results from biopsy of 131 masses.Results-There were 109 benign, 6 high-risk, and 16 malignant masses, with a median size of 12 mm (range, 4 to 48 mm) on conventional US imaging. Of 131 masses, 93 (71%) enhanced on CEUS imaging, including 73 of 109 (67%) benign, 6 of 6 (100%) high-risk, and 14 of 16 (87.5%) malignant. Thirty-eight lesions did not enhance, including 36 of 109 (33%) benign and 2 of 16 (12.5%) malignant. Prediction models using recursive petitioning revealed that CEUS may reduce 31% (95% confidence interval, 23%, 40%) of benign biopsies for masses that are: nonenhancing with circumscribed margins or enhancing with an oval shape and homogeneous enhancement. Quantitative parameters indicated that benign masses had the longest time to peak (P = .078), highest time-topeak ratio of mass to background (P = .036), lowest peak intensity (P = .021), and smallest difference in peak intensity between the mass and background (P = .079) compared to high-risk and malignant lesions.Conclusions-Contrast-enhanced US may be a valuable modality that can be used to predict benign pathologic results of breast masses, thereby reducing the number of biopsies.