Liposarcoma usually occurs in the deep soft tissue of the extremities and the retroperitoneum. It rarely occurs in the cutaneous or subcutaneous tissues. We describe the case of a subcutaneous liposarcoma in a 63-year-old man, which arose from the chest wall. Magnetic resonance imaging showed a large subcutaneous tumor. Incisional biopsy revealed mature adipose cells with a slight variation in size and shape; no lipoblasts were observed. Therefore, at this stage we made the diagnosis of lipoma. However, the histological study of the tumor specimen subsequently obtained by surgery, showed mature adipose cells, atypical cells with bizarre nuclei, and lipoblasts with scalloped-shaped nuclei. We eventually diagnosed the tumor as a well-differentiated liposarcoma, adipocytic type (lipoma-like type). Patients with cutaneous and subcutaneous liposarcoma have a good prognosis, but there are reports of local recurrence after a long period, as well as high-grade change and dedifferentiation. Careful follow-up is required.