PURPOSE: To determine the value of mammography compared to clinical examination in evaluating residual cancer of locally advanced breast carcinoma treated with neoadjuvant chemotherapy. MATERIALS AND METHODS: Among 67 patients with locally advanced breast carcinoma who were treated with neoadjuvant chemotherapy, 18 patients (age:35-67, mean:48) had taken the mammography before and after neoadjuvant chemotherapy. Those 18 sets of mammography were analyzed retrospectively and compared with the result of clinical examination on the basis of histologic diagnosis. RESULTS: On histologic examinations, 16 of 18 patients (88%) had residual cancer, one of them was diagnosed to have no residual cancer in mammography. On mammographic findings, 16 patients were determined to have residual cancer, and one of them was found not to have residual cancer on histologic examination. Clinically, there were 4 patients showed complete response, 11 patients with partial, and 3 with no response. 3 of 4 patients with complete clinical response were found to have residual cancer in histologic examination. In posttreatment mammographic findings, 11 patients were noted to have measurable mass, 8 patients had microcalcifications. All 11 patients with measurable mass in mammography had residual cancer (positive predictive value:100%). However, 5 of 7 patents who showed no measurable mass in mammography had residual cancer. 7 of 8 patients showing microcalcifications in mammography revealed to have residual cancer (positive predictable value: 88%). Sensitivity of mammography in predicting residual cancer was greater than that of clinical examination (94% vs 81%), even when microscopic residual cancer was considered as a complete response (92% vs 77%). Specificity of mammography were same as those of clinical examination (50% vs 50%, 20 % vs 20%). CONCLUSION: Mammography is more accurate and offers more information than clincal examination in evaluating residual cancer of locally advanced breast carcinoma after neoadjuvant chemotherapy. However, prediction of residual cancer with mammography is not accurate enough to replace histologic examination.