A patient with Pseudomonas aeruginosa pneumonia treated with gentamicin subsequently developed thoracovertebral osteomyelitis over the area of a preexisting compression fracture. Increasing back pain and progressive destruction with sclerosis of the involved vertebrae led to a needle biopsy examination of the vertebrae which showed evidence of chronic osteomyelitis and grew P aeruginosa on culture. P aeruginosa bacteremia was documented six months before the demonstration of the organism in the vertebrae. Treatment with a combination of gentamicin and carbenicillin coupled with bed rest cured the vertebral osteomyelitis.