This is a report of an hydrocephalic adult, in whom a unishunt system migrated upwards into the ventricle despite using the appropriate clips (lock and slip). The shunt migration discovered 3 months following its insertion. Several mechanisms contributed to the migration; negative sucking intra-ventricular pressure, positive pushing intra-abdominal pressure, tortuous subcutaneous track and neck movements. It seams that lock and slip clips are not enough fixation. The best way of preventing such shunt migration is interposing a reservoir between the ventricular and peritoneal catheters.