AIM: To report the abnormal type of the orbital liposarcoma -- dedifferentiated subtype in a patient. METHODS: A case report. RESULTS: A 23 years old Chinese woman with a recurrence of right-sided proptosis was evaluated. Ocular examination revealed proptosis of the right eye with chemosis, hyperemia and limitation of eye movements. Magnetic resonance imaging scanning showed an irregular shaped tumor in the right orbit. The tumor resection was done with a clinical diagnosis of malignant tumor. Histopathological findings revealed the diagnosis of dedifferentiated liposarcoma. CONCLUSION: The rare occurrence of this tumour should be kept in mind while dealing with orbital tumours.