Background & Objectives: EP represents mass responses of cortical and subcortical visual areas and are widely used to quantify the state of maturity of CNS. Of the 5 waveforms recorded in VEP, P100 is the most stable. It is studied with respect to latency and amplitude which determines the speed of conuction of the visual pathway and visual acuity respectively. There exists a controversy as to the age of onset of increase in latency and decrease in amplitude of P100. Thus this study was aimed to delineate ageing changes in latency, amplitude and duration of P100 quantified using 15′ (min arc) check stimulus. Methods: The study group constituted of 61 subjects aged between 10-70 years, divided into three groups: Group I: 10-30 yrs, Group II: 31-50 yrs, Group III: 51-70 yrs. The recording was done using Medtronic keypoint computer with three channel recording and occipito frontal (Oz-Fz) montage. Results: Results showed significant increase in mean values of latency in Group III (P<0.01). The amplitude of P100 waveform showed decrease in Group III (P<0.01). The duration of waveform did not show correlation with age. Interpretation & Conclusion: Thus the present study has shown that the latency of P100 increases after 5th decade possibly due to cortical, subcortical and ocular changes due to age. The decrease in amplitude of P100 can be reiterated to deteriorating visual acuity with age, but there was no correlation of duration P100 wave form with age. © 2009 Elsevier B.V., All rights reserved.