A new system has been developed for the non-invasive monitoring of intracranial pressure (ICP) across the anterior fontanelle in the newborn. The system comprises a very small pneumatic sensor linked via two vinyl tubes to an instrument where the ICP value is displayed. The sensor is simply bonded to the anterior fontanelle, using industrial collodion normally used for attaching EEG electrodes. The sensor body is injection moulded in semi-flexible polyurethane with a very thin, compliant membrane bonded to its front surface. Using these manufacturing techniques the sensors are made to be disposable thus minimizing the risk of cross infection. ICP characteristics can now be recorded continuously in a wide range of neonates and the evaluation of currently used therapeutic treatments for lowering elevated ICP can be carried out safely and accurately.