There have been some reports of coincidental presentation of breast carcinoma and phyllodes tumor in the same breast. Most of the cases were carcinoma that arose from a phyllodes tumor with a histologically identified transitional area, and they behaved less aggressively than the usually encountered carcinoma. Collision tumors are rare clinical entities in which two histologically distinct tumor types show involvement at the same site. The occurrence of these tumors in the breast is extremely rare. Here, we report a case of 45-year-old woman who had both invasive ductal carcinoma as the finding of inflammatory carcinoma and a malignant phyllodes tumor in the same breast. There was no evidence of a transitional area between the phyllodes tumor and the invasive ductal carcinoma. To our knowledge, this is the first report of a collision tumor of inflammatory breast carcinoma coincident with a malignant phyllodes tumor in same breast.