The authors discuss the results from a series of 45 patients with breast lumps. All patients were studied by means of mammography, sonography, color Doppler US, and biopsy. Abnormal Doppler signal was observed in 94% of the patients with breast cancer. However, this finding is not specific because it can be occasionally found in benign lesions too. The use of color Doppler US is suggested in those cases where neither US nor mammography is conclusive.