AIM: To report a rare case of mesenchymal chondrosarcoma in the orbit and to explore its clinic manifestations, pathologic characters, management and prognosis. METHODS: We report a case of mesenchymal chondrosarcoma of the orbit. The clinical materials, including ophthalmological examination, computed tomography scan of the orbit, histopathology and immunohistochemistry of the biopsy specimen were reported, and its pertinent literatures were reviewed. RESULTS: A 36-year-old female was seen with proptosis and decreased vision. Histopathology demonstrated an admixture of undifferentiated mesenchymal cells and islands of mature hyaline cartilage. Immunohistochemical studies revealed positivity for vimentin and S-100, which was consistent with the diagnosis of mesenchymal chondrosarcoma. · CONCLUSION: Mesenchymal chondrosarcoma in the orbit is extremely rare malignant tumor. Multi-modality treatments (surgery, chemotherapy and radiotherapy) may lead to long-term survival.