The authors report 10 cases of spontaneous pyogenic spinal osteomyelitis encountered within a 3-year period. There were six women and four men, ranging in age from 60 to 84 years. Six cases occurred at the thoracic level, three at the lumbar level, and one in the cervical spine. No patient was diabetic, immunocompromised, or receiving steroid therapy, and none had a history of endocarditis or intravenous drug abuse. No patient had undergone previous spinal surgery. There were no instances of coexisting tuberculosis or malignancy. Contemporaneous cases with known predisposing factors have been excluded from this report; however, three patients did have a recent history of somatic infection, one with known sepsis. All 10 patients had been previously misdiagnosed, frequently by neurosurgeons and orthopedists as well as by internists and family practitioners. Three had undergone inappropriate or unnecessary surgical procedures, and two had received inappropriate radiation therapy. Seven cases were caused by Staphylococcus species. Gram-negative bacteria, or anaerobic infections. In the other three, no bacteriological diagnosis was made, secondary to prolonged antibiotic therapy before surgery. Each patient had developed symptomatic neural element compression, spinal instability, or both by the time of their referral. The patients with subcervical pyogenic spinal osteomyelitis underwent transthoracic or retroperitoneal decompression and corpectomy with simultaneous autologous bone grafting, followed by 6 weeks of bed rest and 6 weeks of intravenous broad-spectrum or organism-specific antibiotic therapy. They were then mobilized in orthoses for an additional 6 weeks. In no case were foreign implants employed or further stabilization procedures necessitated. One patient required an additional 6 weeks of antibiotics for recalcitrant Pseudomonas colonization. Despite the patients' advanced age and the extensive surgical procedures, there was no mortality and no neurological morbidity. All patients were asymptomatic or demonstrated objective improvement upon discharge from the hospital. In this subset of patients with spontaneous pyogenic vertebral osteomyelitis, the only predisposing factor was advanced age.