Among 105 cases of infectious spondylitis diagnosed and treated from 1971 through 1990, 23 were due to tuberculosis (TS) and 82 to other causes (NTS). The annual number of cases of NTS rose over the study period, partly because of an increase in iatrogenic spondylitis, whereas the number of TS cases fell. In both groups, mean age of patients was higher than in earlier studies. The leading causative agents in NTS were staphylococci, followed by streptococci, then Escherichia coli. Diagnosis of spondylitis was dependent on the imaging techniques used; among available methods, the most reliable was magnetic resonance imaging which improved diagnostic performance by detecting early, specific changes. Except in patients with positive blood cultures and in TS patients with Koch bacilli recovered from other visceral foci, bacteriologic diagnosis rested on studies of samples taken from the spinal infection site. Half the subjects underwent discovertebral needle biopsy, with a success rate of 47.5%, a figure comparable with those reported in other studies. In 30% of patients, bacteriologic documentation of the infection was not obtained and diagnosis rested on a set of clinical, biological, and radiological criteria.