18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT)imaging is valuable in biopsy guidance, response assessment, grading, follow-up and prognostication for soft-tissue sarcoma. In liposarcoma, the maximum standardized uptake value (SUVmax) on PET/CT scan is correlated with the histological subtypes. We briefly review the role of FDG PET/CT in liposarcoma, and describe a case of chest wall liposarcoma treated based on the assessment with PET/CT. A 76-year-old man, with a 10-cm tumor at the thoracic outlet of the right chest wall, underwent the complete resection of the tumor according to the assessment with PET/CT that showed high FDG uptakeonly in the central area of the tumor with SUVmax of 5.89, but low uptake in the peripheral area. In accordance with the PET/CT findings, pathological examination revealed dedifferentiated liposarcoma in the central area and well-differentiated liposarcoma in the peripheral area. Pretherapy PET/CT should be performed for the appropriate treatment of liposarcoma.