Twenty-four patients who had an osteochondral fracture of the dome of the talus were examined by plain radiography, magnetic resonance imaging, computerized tomography, and, when indicated, scintigraphy. When plain radiographs of the ankle are relied on for the diagnosis of an osteochondral fracture of the talus, many lesions remain undiagnosed. Stage-I osteochondral fractures show no diagnostic changes on plain radiographs, and Stage-II lesions are usually subtle and, therefore, are often overlooked by both radiologists and clinicians. The use of scintigraphy as a screening procedure and of magnetic resonance imaging for patients who have positive scintiscans showed that osteochondral fractures are more common than has previously been indicated in the literature. Scintigraphy should be used to assess patients when there is clinical suspicion of an osteochondral fracture but the plain radiographs appear to be negative. Patients who have positive scintiscans should be assessed by magnetic resonance imaging. Patients who have abnormal plain radiographs will derive no major benefits from magnetic resonance imaging; for all but one of these patients, computerized tomography was adequate for staging the fracture.