Osteoid osteomas and osteoblastomas have similar histologic characteristics, although their clinical course in the spine may be significantly different. At the authors' institution, spinal osteoblastomas constituted 46% (30/65) of all osteoblastomas treated. Sixteen of the lesions occurred in the lumbar spine (53%), eight in the thoracic spine, and six in the cervical spine. In all regions of the spine, the posterior elements and pedicles were more frequently involved than the vertebral body. Twenty patients had pain or other symptoms for more than 12 months before diagnosis. Six of eight patients had thoracic lesions that demonstrated neurologic involvement. Twelve patients presented with painful scoliosis. Fourteen patients had lesions with well-circumscribed margins confined within the vertebral structure (Enneking Stage 2), and 16 had ill-defined margins with soft-tissue extension (Enneking Stage 3). Well-defined lesions were treated with curettage, with excellent results in 12 of 14 patients. The more extensive lesions were treated by intralesional excision (15/16) and adjuvant radiation therapy (9/16).