Flash visual evoked potentials (VEPs) were recorded from 67 infants of < 33 weeks gestation with normal neurological outcome at 24 months corrected age. Cross sectional and longitudinal data showed the emergence of peak components of the waveform with increase in maturity. The first major negative peak, with a latency around 300 ms in the most immature subjects, was the most prominent and consistent component. This peak showed a decrease in latency with increase in post-conceptional age, maturing by a mean rate of 5.5 ms/week. The role of VEPs in predicting brain injury in preterm infants can be determined.