A case report of an extremely rare condition describing lumbar spine tuberculosis associated with concurrent pyogenic infection is presented. To establish that isolation of pyogenic bacteria from an infected spine does not exclude the possibility of spine tuberculosis. During a MEDLINE data search from January 1960 through October 2001, no cases of combined spine tuberculosis and pyogenic infection were found. A 52-year-old man reported left-side gluteal swelling, backache, and fever of 20 days duration. A similar swelling in the same location had occurred 12 years previously, and an operation was performed at that time. Preoperative syringe-aspirated material from a gluteal abscess was sent for ordinary bacteriologic culture (for only aerobic pyogenic bacteria). During the operation, a needle-aspirated specimen of evacuated pus was subjected to direct microscopy and culture. Direct Gram stain for pyogenic bacteria and direct Ziehl-Neelsen stain for mycobacteria were performed. Cultures for aerobes, anaerobes, mycobacteria, and fungi were made. The preoperative specimen culture showed growth of Nocardia asteroids and Moraxella catarrhalis, whereas the operative specimen showed Gram-positive cocci and acid-fast bacilli on direct smears. The operative cultures yielded growth of Nocardia asteroids, Moraxella catarrhalis, and Mycobacterium tuberculosis. Plain lumbar spine radiograph showed psoas muscle calcification. It is concluded from this case that recovery of pyogenic bacteria from an infected spine does not exclude spine tuberculosis. It is recommended, therefore, that mycobacterial investigations be performed for cases that have evidence of tuberculosis, even when pyogenic microorganisms already have been isolated. The clues that raise suspicion of tuberculosis in patients with pyogenic spine infection include chronic infection that does not respond to ordinary antibiotics, isolated pyogenic bacteria of low virulence, psoas muscle calcification, and immunosuppression.