A 30-month prospective study was conducted on 43 children who presented with clinical findings suggestive of acute hematogenous musculoskeletal infection. Magnetic resonance imaging (MRI) was found to be extremely sensitive (0.97) and specific (0.92) in helping to diagnose these infections, with only one false positive and one false negative study. Bone scans are more likely to yield false positive and negative examinations. MRI is particularly useful in difficult cases in which there are conflicting clinical data or infection involving the spine or pelvis. After MRI demonstrates the location of the disease process, histologic and/or bacteriologic confirmation of the etiology is still mandatory.