PURPOSE: The modified triple test (MTT; physical examination, ultrasonography, and fine-needle aspiration cytology) for palpable breast masses yielded 100% diagnostic accuracy when all 3 components were concordant (all benign or all malignant) in our previous study. However, about 30% of cases were discordant and required open or core needle biopsy. This study is designed to evaluate the modified triple test by scoring system, based on our experience, and to develop a method to further limit the need for surgical biopsy of discordant cases. METHODS: The MTT was performed in 175 palpable breast masses of 166 female patients between August 1998 and June 2001 at the Outpatient Clinic, Department of Surgery, Chungbuk National University Hospital. Each component of the MTT was assigned 1, 2, or 3 points for a benign, suspicious, or malignant result, respectively, yielding a total modified triple test score (MTTS) from 3 to 9 points, and 25 cases with 3 points of MTTS were clinically followed up without histological confirmation. RESULTS: Among 175 cases, concordant cases were 120 (68.6%); benign cases was 66 (37.7%), and malignant cases were 54 (30.8%). Concordant cases had 100% of diagnostic accuracy, sensitivity, and specificity. Among the 25 cases of benign concordant (MTTS 3 points), no case was proved to be malignant through clinical follow-up observation. Total discordant cases were 55 (31.4%); 15 cases of 4 points(8.6%), 11 cases of 5 points (6.3%), 4 cases of 6 points (2.3%), 18 cases of 7 points (10.3%), 7 cases of 8 points (4.0%). In each discordant group, 0 cases of 4 points (0%), 2 cases of 5 points (18.2%), 3 cases of 6 points (75%), 15 cases of 7 points (83.8%), and 7 cases of 8 points (100%) were proved to be malignant by histologic confirmation. Aspiration cytology has the highest specificity and positive predictive value of the 3 MTT components. CONCLUSION: Palpable breast masses that score 3 or 4 points by MTTS are benign and could be clinically followed up, and masses that score 8 or 9 points are malignant and should undergo defiitive therapy. Confirmatory biopsy might be applied on only 20% of the masses the reserve MMTTS of 5, 6, and 7 points.