A 75-year old woman presented with diffuse left breast enlargement, redness, edema, and a firm palpable lymph node with skin fixation in the left axilla. The tumor was diagnosed as invasive ductal carcinoma with a strongly positive human epidermal growth factor receptor 2 (HER2) score (3+). She was diagnosed as having inflammatory breast cancer (IBC) (T4d N2M0, stage IIIb). The patient received primary systemic chemotherapy with 4 courses of epirubicin 75 mg/m(2) and cyclophosphamide 500 mg/m(2) every three weeks, then 12 courses of paclitaxel 80 mg/m(2) and trastuzumab 2 mg/kg (initially 4 mg/kg) weekly. Six months after the start of chemotherapy, a left modified radical mastectomy with axillary dissection was performed. No cancer cells in the breast specimen and no metastases to the axillary nodes were observed, so the therapeutic effect was determined as a pathological complete response (pCR). This report suggests that combination therapy with epirubicin and cyclophosphamide followed by trastuzumab and paclitaxel was useful for HER2-positive IBC.