Sarcoma of the breast constitutes <1% of all malignant breast tumors, and liposarcoma of the breast represents 3-24% of the primary breast sarcomas. We report a case of a 74-year-old woman presenting with liposarcoma of the left breast. The patient presented with a fibrous and hard mass measuring approximately 10 x 5 cm in diameter in the upper part of the left breast. Aspiration breast cytology showed inflammatory changes and had no malignant element. Differential diagnosis with sonography, computed tomography, and magnetic resonance imaging was not successful. A wide excision was performed with a 2-cm margin of healthy tissue. The tumor was diagnosed histologically as a well-differentiated liposarcoma (sclerosing type). The patient was discharged and her recovery was uneventful. We report a case of liposarcoma of the breast and discuss this rare malignant tumor and other types of sarcoma of the breast in light of the previously published literature.