Phyllodes tumors (PTs) are a group of rarely breast tumors of fibro-epithelial origin, counting for about 1% of the breast malignancies divided, based on histological features, in benign, borderline and malignant neoplasms, arising most of them in women in their 40's. Among this complex group of tumors, the liposarcomatous differentiation is an even more rare lesion, counting for about 0.3% of all primary sarcomas of the breast. This article presents a case of a 48-year-old woman with a breast malignant PT with liposarcomatous differentiation, diagnosed by guided core biopsy, treated by excision and subsequent simple mastectomy followed by radiotherapy, with a 3-year follow-up.