The authors reviewed 1 year of experience with planar and single photon emission computed tomographic (SPECT) bone scintigraphy in 162 young patients with symptoms of low-back pain possibly related to stress injury to the pars interarticularis or spondylolysis. Planar scintigraphy and SPECT revealed no abnormality in 91 patients (56%). All abnormalities detected on planar images were also detectable with SPECT. SPECT showed an abnormal focus of radiotracer uptake in the lumbar spine in 71 patients (44%). In 32 of these 71 patients, these findings were also evident with planar scintigraphy. In 39 of these 71 patients, use of SPECT. Correlation with contemporaneous radiographs was made in 72 cases (including computed tomography in 10 cases). SPECT can be used to detect stress injury not seen with planar bone imaging or radiography and is recommended in evaluation of low-back pain in young athletes.