There is no general agreement about the influence of the behavioural states on the visual evoked responses. In the present study visual evoked potentials (VEP) were recorded in 6 preterm and 6 full-term newborns in the different behavioural states. A significant increase in the amplitude was observed from sleep to awake states in both preterm and full-term infants. The results supply information in favour of the utility of the behavioural assessment when VEP are recorded. It reduces the variability of the results providing for more reliable normative data.