A system is described for the rapid analysis of the extensive EEG data produced by continuous 4-channel monitoring. Using this system, the initial EEGs of 44 low-risk preterm infants between 26 and 37 weeks gestation have been analysed and quantified in order to establish standard values. This provides a basis for assessment of the acute EEG as an index of cerebral function in high-risk or abnormal preterm infants.