At the Tenon Hospital (Paris), 48 inflammatory or locally advanced breast cancers were treated by neoadjuvant chemotherapy (three different protocols), followed by surgery (mastectomy or tumorectomy and axillary dissection). The histological data of the specimens are analyzed with regard to the clinical and radiologic evolution. Twenty complete clinical responses (41%), 22 partial clinical responses (45%), and no response in six cases (14%) were observed. Histology demonstrated residual tumors in 42 cases (87.5%), even in the case of complete clinical response (14 cases), without notable change of the grade (SBR). Lymph node clearance demonstrated positive nodes in 38 cases (79%). Despite its great agreement with clinical examination, mammography does not predict the existence of histological residual tumors after initial chemotherapy. Chemotherapy allowed local treatment, but can rarely sterilize the tumor completely.