Paravertebral osseous masses in reptiles have been attributed to Paget's disease on the basis of histology. Histologically recognized mosaic architecture and cement lines, however, lack specificity. A Varanus dorianus with this condition was subjected to standard and computerized tomography. Because the masses were extraskeletal in nature, Paget's disease could be excluded. Although interpretation of the computed tomography suggested the process to be entirely extraskeletal, standard radiographs revealed disorganized vertebral architecture characteristic of osteomyelitis, crossing intervertebral spaces. Posttraumatic myositis ossificans and calcified hematoma were confidently excluded as diagnoses. The etiology of paraspinal masses in this V. dorianus appears attributable to infection, with infection of a puncture wound hypothesized as the underlying process. If one extrapolates the findings in this one animal, it seems reasonable to suggest that consideration be given to investigating the possibility of an infectious origin when similar masses are recognized in other reptiles.