The diagnosis of vertebral osteomyelitis is easily missed, particularly for the elderly in whom signs of sepsis may not manifest. The case records of 20 patients with vertebral osteomyelitis who were treated at our hospital between January 1989 and April 1993 were reviewed. The average age of the patients was 72 years. Infection was most commonly due to intravenous cannula-related sepsis. Eighty-five percent of patients presented with back pain, and only 30% had a fever. Computerized tomography and magnetic resonance imaging were the most useful radiological investigations; nuclear scanning was sensitive but insufficiently specific. Staphylococcus aureus was the infecting organism in 13 of 16 patients whose microbiological diagnosis was made by blood or bone cultures. Six (45%) of these 13 patients were infected with methicillin-resistant S. aureus (MRSA). Nosocomial infection occurred in 12 (60%) of the patients studied, including all patients with MRSA infections. Vertebral osteomyelitis may be largely preventable if infection-control aspects of intravenous cannulation are improved, attempts at reducing and preventing MRSA colonization are made, and therapy for bacteremias is optimized.