This study describes the clinical presentation, magnetic resonance imaging (MRI) features, surgical treatment, and outcome of an unusual extradural vertebral chondrosarcoma in a dog. A 6-year-old neutered male Poodle-Terrier with an extradural chondrosarcoma diagnosed at the level of the T11 vertebra, following surgical excision by dorsal laminectomy. Clinical, radiographic, MRI, histopathologic, and postoperative rehabilitation data were assessed. Following the sudden onset of pelvic limb paralysis in the dog, MRI revealed a lobulated, extradural mass at the T11 vertebra (13 × 7 mm) hyperintense on T2-weighted images, causing compression of the spinal cord. Surgical removal revealed a chondrosarcoma with a soft, pale pink to white gross appearance. Rehabilitation following surgery, including physiotherapy, hydrotherapy, and laser therapy, resulted in weight-bearing recovery within 3 months, while the dog never acquired the ability to stand without support until 9 months despite 80 sessions of physiotherapy. No metastasis was observed after surgery. This case exemplifies the diagnostic utility of MRI for detection of extradural spinal tumors and potential surgical resection for improving quality of life, but long-term prognosis can be reserved due to incomplete functional recovery and local aggressiveness of the tumor.