A 23-year-old woman presented with right-sided painless proptosis that developed in 12 months. MRI studies demonstrated a well-delineated tumorous enlargement of the right lacrimal gland with homogenous signal intensity and compressing the globe. The tumor was removed totally and in 1 piece with the tentative diagnosis of a pleomorphic adenoma. Pathologic examination revealed biphasic neoplastic elements, which were composed of the cartilaginous matrix and small round cell component. Immunohistopathological examination showed positive CD99 staining and negative reaction to S100, panCK, and CD15. The patient then received a total of 64 Gy orbital radiotherapy in 32 fractionations. There has been no recurrence or metastasis during 14 months of follow up. This case showed that mesenchymal chondrosarcoma may arise from the lacrimal gland and must be considered in the differential diagnosis of lacrimal gland tumors in young adults.