STUDY DESIGN: A case report is presented of destructive lesion involuting intervertebral disc space and adjoing vertebral bodies in association with ankylosing spondylitis. OBJECTIVE: To report unusual clinical and radiological presentation of spondylodiscitis and its treatment wi th anterior interbody fusion. SUMMARY OF BACKGROUND DATA: Althought there is some mention in the literature of pathogenesis, diagnosis and treatment of spondylodiscitis in ankylosing spondylitis, we think that its occurrence is frequent enough to warrant this condition and we should differentiate it from other infectious or tumorous condition. RESULTS: Anterior debridement and anterior interbody fusion with structural bone graft were performed. The microscopic study showed nonspecific chronic inflammation and extensive necrosis. CONCLUSION: It was suggested that primary spondylodiscitis or pseudoarthrosis resulted from mechanical trauma be related to this condition rather than infectious spondylitis.