The aim of the present study was to assess the ability of a novel bone imaging technique to diagnose accurately the cause for back pain as an isolated and presenting complaint in adolescents. An integrated 18F-fluoride positron-emission tomography-computed tomography (PET-CT) study was performed at the same setting without changing the patients' position, followed by generation of fused images of functional and anatomical data. Fifteen subjects were included in the study. The interpretation of PET-CT fused images was based on increased 18F-fluoride uptake and the corresponding CT-located abnormality. Ten patients had positive findings that included 4 cases of spondylolysis (3 of them active), 3 frank fractures (2 of the transverse process and 1 of the facet), 2 osteoid osteomas, 1 osteitis pubis, 1 sacroiliitis, and 2 herniated disks. Three patients presented 2 coexisting pathologies. Treatment was tailored based on final diagnosis. In 5 patients, in whom no abnormality was identified, the back pain resolved spontaneously. The 18F-fluoride PET-CT can detect spinal lesions with high diagnostic accuracy in adolescents with back pain. Considering the associated costs and radiation exposure, it should be used at present only in cases of long-standing and disabling back pain in which other imaging modalities were inconclusive.