A retrospective analysis of 434 patients with vertebral tuberculosis who were treated surgically was performed with special reference to the preoperative duration of chemotherapy. Of these, 376 underwent 4 weeks of a chemotherapy regimen with isoniazid, rifampin and ethamburol, and in 2 re-activation of the disease was observed. The remaining 58 underwent operation for neurological impairment with 6-18 h of the same chemotherapy regimen, and in no case did re-activation occur. These results suggest a shorter duration of chemotherapy may be utilised in all patients undergoing surgical treatment for vertebral tuberculosis, providing a thorough debridement is performed, leaving no necrotic or infected tissue behind.