Liposarcoma is one of the most common soft-tissue sarcomas in adults; however, pleural and mediastinal liposarcomas are exceedingly rare. Primary pleural liposarcoma (PPLS) is divided into well-differentiated, dedifferentiated, myxoid, pleomorphic, and myxoid pleomorphic subtypes. The tumors can be incidentally discovered on thoracic imaging in asymptomatic patients. More often, a large PPLS can exert a mass effect on adjacent structures, leading to symptoms such as shortness of breath, chest pain, and cough. Thoracic imaging with computed tomography can reveal a heterogeneous mass occupying a significant portion of the hemithorax, often with septations and nodules, providing valuable diagnostic clues. Definitive diagnosis requires histopathologic analysis. In cases of ambiguous histopathologic features, genetic analysis and fluorescent in situ hybridization can aid in establishing the correct diagnosis. Curative treatment relies on complete surgical resection. Radiation and chemotherapy have been used rarely with varying results.