An intravertebral vacuum phenomenon was observed within 19 vertebrae of 17 patients. It represents a non-healing vertebral fracture. Three possible pathologic mechanisms are discussed: ischemic bone necrosis, trauma with ensuing ischemic necrosis, and intraosseous disc prolapse. The intravertebral vacuum phenomenon was found in two patients with multiple myeloma and thus does not exclude the presence of malignancy in the affected bone. Radiographs obtained during traction or extension may be of diagnostic value.