PURPOSE: Dermatofibrosarcoma in the orbit is a rare malignant neoplasm. We report an extremely rare case of primary dermatofibrosarcoma in the orbit. CASE SUMMARY: A 66-year-old male presented with a slowly progressing periorbital mass on his left upper eyelid which developed 3 weeks earlier. On physical examinations, a palpable firm mass under the skin was observed at the superomedial aspect of the left upper eyelid. However, there was no surface nodule or demarcated line on the eyelid. An approximately 1.2 × 1 × 1 cm sized well defined and clearly demancated mass was observed on orbital computed tomography. Excisional biopsy was performed under local anesthesia and pathological examination revealed dermatofibrosarcoma. There was no metabolic evidence of regional or distant metastasis based on positron emission tomography-computed tomography. Nine months after surgical excision there was no evidence of local recurrence. CONCLUSIONS: This is the first report in South Korea of dermatofibrosarcoma in the orbit. Dermatofibrosarcoma should be considered following differential diagnosis of a periorbital mass.