Mesenchymal chondrosarcomas are rare malignant tumors of the bone and soft tissue. Spinal mesenchymal chondrosarcomas are even rarer and, to the best of our knowledge those that are concomitantly located in the intradural and extradural regions, have never been reported. We report a case of a 25-year-old man with back pain and bilateral progressive weakness of the lower extremities. Magnetic resonance imaging revealed a markedly enhanced dumbbell-shaped mass at the T7 level. The lesion was intradurally located at the left side of the spinal cord, and extended extradurally to the extraforminal space through the T7-8 intervertebral foramen. The tumor was completely excised through a posterior approach. Microscopic examination and immunohistochemical studies confirmed mesenchymal chondrosarcoma. Postoperative radiation therapy and chemotherapy were also performed to prevent local recurrence and metastasis. The patient has been symptom-free for two years after surgery. Herein, we reviewed and discussed the clinical characteristics, treatments, and outcomes of primary intraspinal mesenchymal chondrosarcomas in the literature.