We describe a case of retrovesical liposarcoma in a male patient with concurrent COVID-19. A 50-year-old man had lower urinary tract symptoms and dull pain along his right gluteus. Due to COVID-19 infection, management was delayed. During self-isolation, the patient developed urinary retention and his pain level was an eight on the Visual Analogue Scale. A urinary catheter and an epidural catheter were inserted without any difficulty. Abdominal-pelvic MRI revealed a retrovesical mass suspected of liposarcoma with clear borders from surrounding organs. Following two consecutive negative SARS-CoV-2 PCR tests, we proceeded with surgery. Histopathology was dedifferentiated liposarcoma. Postoperatively, the patient suffered reactivation of COVID-19, and he was eventually discharged after two consecutive negative results on the PCR test on Post Operative Day (POD)-10. Retrovesical dedifferentiated liposarcoma is rare and considered as high-grade liposarcoma. Although surgery may exacerbate COVID-19 infection, surgical resection of symptomatic high-grade sarcoma is prioritised and performed as soon as no infection detected.