&NA;Granulocytic sarcoma (GS) usually occurs during the course of, or as a presenting sign of myelogenous leukemia. Rarely it is found before peripheral blood or bone marrow evidence of leukemia is present. We describe a man who presented with low back pain and lower extremity weakness. He had spinal cord compression due to GS without evidence of leukemia. Only four such instances have been previously reported. Such aleukemic presentations of GS are frequently misdiagnosed. The chloroacetate esterase stain and electron microscopy are useful in demonstrating the myeloid origin of GS cells. GS lesions are probably best treated by localized radiation therapy and systemic chemotherapy. (Neurosurgery24:125‐128, 1989)