We report a case of isolated intramedullary sarcoidosis. The patient developed progressive signs that indicated a spinal tumor, which were investigated with contrast-enhanced magnetic resonance imaging scans. Magnetic resonance imaging clearly revealed an intramedullary lesion, but the diagnosis of sarcoidosis was made on the pathological analysis of the surgical specimen. Magnetic resonance imaging with contrast enhancement is reported in a histologically proven case of intramedullary sarcoidosis. Only 12 other cases of isolated intramedullary sarcoidosis have been reported. We review and discuss these cases according to their clinical presentation, the segmental location of the granulomas in the spinal cord, preoperative and operative diagnoses, and signs for systemic sarcoidosis. In none of the cases was the diagnosis of intramedullary sarcoidosis made before surgery. We think that surgical therapy for intramedullary lesions is the best way to diagnose rare instances of benign lesions like sarcoidosis and to treat them in an appropriate manner.