The intracranial, liquid-containing cysts in children (excluding tumor and parasitic cysts) are relatively frequent in neurosurgical practice. They raise several problems about their nosology, etiology, clinical and radiological diagnosis, and treatment which are analyzed in a series of 36 cases of supratentorial cysts. The most frequent clinical feature is increased head circumference (22 cases) followed by epileptic fits (18 cases), as well as mental and motor retardation (19 cases). Fundi were found abnormal in only one case out of three. Electroencephalogram was abnormal in almost every case, showing either spikes, spikes and waves or localized slow waves, or an asymmetric depression of the electrical activity. Radiological investigation is essential for diagnosis. Plain radiographs of the skull may show an asymmetry (11 cases). Carotid angiogram and pneumoencephalography give the diagnosis of the lesion without accuracy as to the histology. Computerized axial tomography shows the position of the liquid cavity within the head. The surgical approach (simple shunting [6], direct approach [19], or both [7]) should be carefully considered according to anatomical variety and age of the child. An anatomical classification is proposed, based on the radiological, surgical and pathological findings. Three types of cysts are defined: external cysts (cortical or extracortical) which may or may not be communicating with the ventrioles or the subarachnoid space; internal cysts which again may or may not be communicating; and the corticoventricular cysts. The ultrastructural study represents further progress in the attempt to define the exact anatomical type.