A review of our recent experience with spinal epidural abscess (SEA) reveals several important changing concepts in diagnosis, etiology, management, and outcome. All cases of SEA seen by our service from August 1975 to July 1989 were reviewed retrospectively, and 29 patients were identified (19 men and 10 women, aged 13-78 years). Abscesses were located in the lumbar (n = 21), thoracic (n = 7), and cervical (n = 1) epidural spaces. Gram-positive organisms were the infectious agent in 72% of the cases, and Staphylococcus aureus was the sole agent in 45%; other agents were Gram-negative aerobes (n = 5), a Gram-negative anaerobe (n = 1), Mycobacterium tuberculosis (n = 1), and Sporotrichum schenckii (n = 1), the last occurring in a young woman with acquired immune deficiency syndrome. Seventeen patients had concomitant extraspinal infections. Diagnosis was confirmed by myelography, computed tomography, or magnetic resonance imaging. All patients underwent operative decompression and debridement; 2 required a second procedure for persistent infection. The most common operative findings were pus and granulation tissue in the epidural space (52%); the preoperative course correlated poorly with operative findings. The wound was closed primarily in 84% of cases. Postoperative intravenous antibiotic courses for the bacterial abscesses ranged from 1.5 to 6 weeks (median, 2 weeks), followed by antibiotics given orally for 0 to 6 weeks. Two patients died perioperatively. Neurological outcome was good in 21 patients and fair in 6 (mean follow-up, 1.4 years). Over the last 50 years the spectrum of organisms causing SEA has broadened, and the distinction between acute and chronic SEAs has minimal clinical significance.(ABSTRACT TRUNCATED AT 250 WORDS)