Objective. The purpose of this study was to assess the value of sonographic examination of congenital variations of the extracranial vertebral artery associated with posterior circulation ischemia in children. Methods. Sonography was performed on the vertebral arteries of 82 patients aged 2.5 to 14 years with a history of headache, vertigo, and syncope. An additional 86 unaffected children aged 2 to 14 years were included as a control group. Indices such as the diameter, passage, and morphologic characteristics of the vertebral artery were measured, as well as the arterial volume. The median values of these parameters were used for comparisons. Results. A comparison between the control and 5 case groups showed that the bilateral diameter and volume in these 6 groups had significant variations (P < .05). A narrow diameter and abnormal passage of the vertebral artery resulted in reduced blood flow and an inadequate blood supply in the posterior circulation. There were 42 cases found to have congenital variations of the extracranial vertebral artery, 12 cases of congenital asymmetry, 15 cases of tortuosity, 5 cases of bilateral congenital asymmetry with tortuosity, 6 cases of congenital hypoplasticity, and 4 cases of an abnormal path. Conclusions. Certain children with a history of recurrent signs of vertigo, headache, and syncope were found to be afflicted with congenital variations of the extracranial vertebral artery. Sonography not only revealed the morphologic variations of the extracranial vertebral artery but also allowed an assessment of changes in blood flow such that posterior circulation ischemia could be determined.