We report a retrospective analysis of all cases of acute knee injuries in children presenting to the Winnipeg Children's Hospital, University of Manitoba, between Jan. 1, 1994, and Jan. 1, 1995. The mechanism of injury was recorded and all 3 radiographic views (i.e., anterioposterior, lateral and skyline) were available for 171 of 256 total cases. We found a significant association between mechanism of injury and visualization of damage on skyline view radiographs (p < 0.01). The skyline view showed damage in only 1 of the 158 cases involving direct or indirect injury not involving subluxation or dislocation. However, damage was visualized on skyline view radiographs in 7 (54%) of the 13 cases that included a history of subluxation or dislocation. We conclude that in acute knee trauma in children, a skyline view radiograph of the patella should be obtained only when the mechanism of injury includes subluxation or dislocation. When the mechanism does not suggest subluxation or dislocation, the skyline view is unlikely to reveal damage; it adds unnecessary radiation, cost and possible added discomfort for the child.