Osteomyelitis in adults due to Haemophilus influenzae is exceedingly rare. We report a case of H. influenzae type b vertebral osteomyelitis in an adult. Review of the English literature reveals one other adult patient with H. influenzae osteomyelitis, and sporadic pediatric cases. Although a variety of predisposing host resistance factors have been postulated to account for this infection, the deficiency responsible for adult infection remains undelineated. Bone biopsy is mandatory for diagnosis when blood cultures are negative. The isolation and identification of H. influenzae may be delayed because of its fastidious growth requirements. Treatment with ampicillin or chloramphenicol appear to be most efficacious considering the antibiotic sensitivities of the organism.