The role of magnetic resonance imaging (MRI) in the evaluation of patients with osteochondral lesions of the capitellum is undefined. To define its role, the cases of nine consecutive children with 11 capitellar osteochondral lesions who underwent MRI were reviewed. Magnetic resonance imaging accurately delineated the size of the osteochondral lesions and identified capitellar loose bodies not seen on plain radiographs in two elbows. In patients without capitellar loose bodies, two distinct MRI patterns existed that were similar to those seen in femoral head osteonecrosis. Magnetic resonance imaging aided in the treatment of children with osteochondral lesions of the capitellum. Further studies are necessary to define the significance of the two MRI patterns.