PURPOSE: To evaluate a scoring system based on ultrasonographic findings as a means of distinguishing between benign and malignant solid breast masses. MATERIALS AND METHODS: Histopathologically confirmed benign (n=102) and malignant (n=73) breast masses which ultrasonographic findings of histopathologic masses were reviewed for shape, border, internal echo, boundary echo, posterior echo, lateral echo, and ratio of transverse to anteroposterior diameter. There were statistically significant (p < 0.001 ; chi-square test) differences in each feature for benign and malignant lesions. The findings suggesting benignancy, equivocality, and malignancy of the masses were scored as 0, 1, and 2 respectively. The scores for all features were summed for each lesion. An ROC curve was obtained. RESULTS: When the score was 6, five benign and seven malignant cases were found. Scores of 0 and 1 indicated benign masses and a score above 11, malignancy. The turning point was a score of 6, so a score above 7 suggests malignancy. CONCLUSION: A ultrasonographic scoring system can be used to characterise breast masses. A score of a mass above 7 suggests probable malignancy and a score below 5 suggests benignancy.