The authors have analyzed a retrospective series of 27 aneurysmal bone cysts (ABCs) in children and adolescents. The average age at diagnosis was 10 years (range: 3 years 7 months to 16 years), with a mean follow-up of 5 years (range: 1 month to 13 years 9 months). Pathologic fractures (8 cases) and pain (8 cases) were the main reasons for consultation. Of five spinal ABC patients, four presented with neurologic involvement. Although conventional radiology is useful for diagnosing ABCs, magnetic resonance imaging (MRI) is nevertheless the most important technique for checking the extent of the lesions. However, the diagnosis still must be based on the pathologic laboratory findings, even though this is sometimes difficult because of associated lesions. In lesions of the long bones, recurrence was observed after curettage in 5 of 12 cases. For this reason, simple resection or resection with reconstruction is recommended rather than curettage whenever possible. When an ABC is in contact with the growth plate in young children, blunt curettage should be performed to preserve the child's growth potential. Subsequent recurrence usually is easier to treat than an epiphysiodesis bridge and its consequences. The surgical procedures used to preserve the growth plate are described, along with methods of bone construction after surgery.