PURPOSE: To investigate the general applicability of ultrasonography (US) and clinical findings in differentiating benign from malignant solid nodules in the subareolar area of the breast. MATERIALS AND METHODS: From March 2001 to March 2003, pathologically proven 84 nodules from 78 patients were included in this study. Two radiologists evaluated the shape, margins, internal echotexture, internal echogenicity, posterior echo intensity and relation with the major ducts, and each nodule was then classified as benign or malignant. Clinical findings were divided into either or absence of symptom. The ultrasonographic, mammographic and clinical classifications were compared with the pathological results. The sensitivity (SE), specificity (SP), positive predictive values (PPV) and negative predictive values (NPV) were calculated for ultrasonographic, mammographic and clinical classifications. RESULTS: Sixteen nodules were proved to be malignant (7 ductal carcinoma in situ and 9 invasive ductal carcinoma), and the remaining 68 nodules were benign. SE, SP, PPV, and NPV of breast cancer according to the ultrasonographical classification were 100%, 61.8%, 38.1% and 100% while those of the clinical classification were 81.3%, 73.5%, 41.9% and 94.3%, respectively. Relation with the major ducts such as ductal communication or intraductal location demonstrated a high SE (87.5%) and NPV (92.0%). CONCLUSION: Ultrasonographic and clinical findings can be helpful in the differentiation of benign solid nodules from malignant lesions in the subareolar area of the breast.