Event-related potentials were recorded from 20 neurologically normal children with anisometropic amblyopia. Stimulation was performed with an 'odd-ball' paradigm counting Randolts' circle, and in all cases N200 and P300 were recorded as event-related potentials. The latencies of N200 showed statistically significant delay (p < 0.001: Wilcoxson signed rank test), but P100 and P300 were not delayed in the stimulus input from amblyopic eyes. The degree of delay has no relationship with visual acuity or anisometropic differences. The results suggest that the cortical sensory processing functions represented by P300 were not damaged in the amblyopic cases observed in this study.