A case of avascular necrosis of the capitellum humeri is reported in an eight-year-old boy; the condition resembles avascular necrosis in other epiphyses. Although its appearance on the roentgenogram is quite ominous, the prognosis is good with a minimum of treatment. However, definite changes in the roentgenological appearance of the elbow in the area of the capitellum usually persist after complete revascularization has occurred. It would be interesting to follow patients with this condition far into adulthood to see how these mildly damaged elbows stand the wear and tear of use. It would also be interesting to see if when the trochlea finally becomes completely ossified it too shows evidence of having been damaged by avascular necrosis at a time when it was almost purely cartilaginous.