A 13-year-old girl presented with pelvic pain and imaging revealed a large right ovarian cystic mass. Histologic examination showed a malignant myxoid tumor with chicken-wire vasculature characteristic of a myxoid liposarcoma. The morphologic appearances were supported by the presence of the rearrangement of the CHOP gene demonstrated by interphase fluorescent in situ hybridization. There was no evidence that this tumor represented metastatic disease. To the best of our knowledge, primary ovarian myxoid liposarcoma has not been previously reported in the English literature. We present the case and briefly discuss the differential diagnosis.