PURPOSE: The "triple test" (TT) which consists of a physical examination (PE), mammography (MMG), and fine needle aspiration (FNA) has been used for diagnosing a palpable breast mass. However, the TT is not always accurate when it is applied to young women. This is because a dense breast hampers the sensitivity of a mammograph. Here, we introduce breast ultrasonography (USG) in place of a MMG (Modified TT; MTT) to determine whether this method can facilitate a correct diagnosis of a breast mass. METHODS: A MTT was performed in 142 palpable solid breast masses from 126 female patients between August 1998 and July 2000 at the out-patient breast clinic, Chungbuk National University Hospital. The breast masses were listed as benign or suspicious/malignant. All patients underwent a subsequent needle biopsy or surgical biopsy for a definitive diagnosis. RESULTS: 78 out of 142 palpable breast masses (54.5%) were benign, while 64 (45.5%) were diagnosed as having breast cancer. In all 105 cases (73.9%) where the MTT was concordant (elements had either all malignant or benign results), a needle or surgical biopsy was confirmatory (predictive values, sensitivity, and specificity 100%). In 37 cases of the non-concordant results, 16 (44.7%) were proven as malignant. The positive predictive value for PE, USG, and FNA was 80.6%, 87.1%, and 100% respectively. The negative predictive value for PE, USG, and FNA was 91.4%, 95.8%, and 91.8% respectively. The sensitivity for PE, USGand FNA was 90.6%, 95.3%, and 89.1% respectively. The specificity for PE, USG, and FNA was 82.1%, 88.5%, and 100% respectively. CONCLUSION: The modified triple test was 100% accurate for diagnosing a palpable breast mass when all three elements were concordant. A palpable breast mass with a concordant benign modified triple test could be safely followed up without a surgical biopsy, and a final treatment could be applied to patients who have had a concordant malignant modified triple test.