Four patients who had received chymopapain injections for treatment of herniated lumbar disks were evaluated by computed tomography (CT) because of persistent low back pain and suspicion of infection. Irregularity of the vertebral end-plate and a mottled appearance of the vertebral bodies suggested the diagnosis of disk-space infection in all four cases. CT-guided biopsy of the disk space was performed in each case, and bacterial cultures demonstrated staphylococcal infections, which were treated accordingly. Diskitis secondary to chymopapain injection is rare because of the precautions that are usually taken. No antibiotics are used routinely with such injections, although systemic antibiotics have been used in diabetics for prophylaxis.