Twenty-three children who were treated for rotatory atlanto-axial subluxation between 1975 and 1986 were retrospectively studied. The success of closed reduction with traction and the length of hospitalization were related to the duration of symptoms before admission. In sixteen of the children, who were seen less than a month after the onset of symptoms, the subluxation reduced either spontaneously or after a short period of traction. Of the seven remaining children, who were seen more than one month after the onset of symptoms, three eventually needed a posterior atlanto-axial arthrodesis. Dynamic computed-tomography scans, with the head rotated maximally to each side, were made for five children, and proved to be an excellent method of documenting the presence of rotatory atlanto-axial subluxation.