The authors report their experience concerning 75 cases of middle fossa arachnoid cysts observed in children during the period 1975-1993, 47 of which (62.6%) were operated upon. The aim of this study was to study the clinical presentation of these cysts, to discuss the surgical indications and to compare the results of the various techniques used to treat these malformations. Head injury was revealing in 17 cases (22.6%) and among these, 12 patients presented intracranial complications (subdural effusions; 6 cases, subdural hematomas: 4 cases and intracystic hematomas: 2 cases). The most usual signs and symptoms were: intracranial hypertension (25.3%), epilepsy (16%) and temporal bulging (24%). Twenty-one patients (44.7%) underwent a cystoperitoneal shunt; 20 patients (42.5%) were treated by membranectomy with opening of the basal cisterns and removal of intracystic (2 cases) or subdural hematoma (4 cases); 2 patients (4.3%) were treated using membranectomy, opening of the cisterns and cystoperitoneal shunt and 4 patients (8.4%) underwent a subduroperitoneal shunt. The long-term results were good regardless of the surgical procedure; nevertheless, only one patient among 20 cases treated by membranectomy and opening of the cisterns developped complications (5%), while multiple shunt revisions were necessary in 11 children (40.7%) out of 27 where a shunt was inserted. The authors conclude that membranectomy and opening of the basal cisterns is the procedure of choice to treat middle fossa arachnoid cysts in children.