In this study the authors discuss the results obtained using pulsed Doppler to evaluate internal mammary artery blood flow velocity in normal, dysplastic and neoplastic breasts. The following parameters were evaluated: percentage of artery localization, vessel diameter, and blood flow velocity. One hundred and seventy-five patients were examined by pulsed Doppler US and mammography in the same sitting. US evaluation of the internal mammary artery was possible in 156 cases. These patients were divided into 3 groups according to Wolfe's classification: normal (38 patients), dysplastic (74 patients) and neoplastic (44 patients). The mean blood flow velocity was estimated in each group; a significant difference was observed between normal (11.8 +/- 6 cm/s) and dysplastic (22.5 +/- 11 cm/s) patients. As for neoplastic patients, similar values were observed in benign (20.6 +/- 9 cm/s) and malignant (25.8 +/- 11 cm/s) lesions. Benign and malignant lesions were distinguished also according to Wolfe's parameters. In the patients with malignant lesions and normal breasts there was an increase in blood flow velocity--which was not observed in dysplastic breasts. In benign lesions in normal or dysplastic breasts, the blood flow velocity was similar to that observed in the respective group of nonpathologic breasts.