The object of providing a cerebrospinal fluid drainage system 1 which reacts precisely to changes in pressure in the cerebrospinal fluid, with ease of operation, is achieved by the present invention in that a pump 5 is used for draining the cerebrospinal fluid (liquor), wherein operating measured values supplied by sensors act as controlled variable for the operation of the pump. The pressure in the liquor line currently measured by a pressure sensor 10, the liquor pressure in the intracranial cavity being treated, measured intracorporeally by a pressure sensor, and/or the volume of liquor already pumped out, as operating measured value, can, for example, serve as the basis for operational control of the pump of the liquor drainage system. The liquor drainage system according to the invention has the advantage that the liquor is drained not only simply on the basis of the excess pressure in the intracranial cavity being treated, but is actively pumped out of the intracranial cavity in a controlled manner, in particular with constant measurement of the liquor pressure. In this way the pumping capacity can be regulated depending on requirement and the drainage pressure or the liquor pressure kept reliably within a specific pressure range.