Radiological diagnosis of Sturge-Weber's disease is based on the recognition of the characteristic "tram-line" type of calcification at routine skull X ray examination. Computerized tomography allows an earlier diagnosis since it shows smaller calcifications. It also provides a better appreciation of the associated parenchimal anomalies, such as cerebral atrophy, and an exact evaluation of the extent of the pial angiomatosis following intravenous injection of contrast. In four children with Sturge-Weber's disease CT clearly revealed the full extent of calcifications and vascular anomaly; in one of the children the diagnosis was possible before the appearance of the calcifications.