We report a unique case of a 42-year-old woman with a dedifferentiated liposarcoma of the soft tissue of the oral cavity with angiosarcomatous dedifferentiation. Liposarcomas compromising the head and neck region are very unusual, and most of the cases in oral cavity show a well-differentiated pattern. Dedifferentiation in liposarcomas occurs in about 10% of the cases and, when it occurs, the dedifferentiated areas usually resemble high-grade fibrosarcoma or pleomorphic sarcoma. Divergent differentiation might also occur. To the best of our knowledge, there are only nine cases of dedifferentiated liposarcoma of the oral cavity, none of which show an angiosarcomatous dedifferentiation.