Sonazoid®, the only ultrasound contrast medium that can be used clinically in Japan, has been covered by insurance for focal breast lesions since August 2012. Contrast-enhanced ultrasound for focal breast lesions is not yet widespread, and a standard protocol and diagnostic criteria are not yet established. A consensus on a contrast-enhanced ultrasound method for breast lesion, phase, and observational points of contrast-enhanced findings will be needed. Based on our clinical experience and reports in the literature, the difference in contrast-enhanced ultrasound between the liver and breast and our opinions on contrast-enhanced methods and evaluation points of contrast-enhanced findings are discussed. Also, when presenting our clinical cases, we describe how contrast-enhanced ultrasound will be useful for the differential diagnosis of malignant and benign breast lesions, assessment of the spread of breast cancer, detection of lesions that cannot be detected by first ultrasonography examination, and assessment of response to chemotherapy.