A search was undertaken for contributions of sustained and transient visual elements to the rat visual-evoked potential (VEP) using procedures similar to those used in humans. Evoked potentials were recorded following either pattern-reversal or pattern-onset stimulation over a range of spatial frequencies, and following adaptation to a stationary grating of the same spatial frequency as the test stimulus. The initial VEP component, a positive peak labeled P1, was early in latency, larger at lower spatial frequencies, larger following pattern-reversal than pattern-onset stimulation, and not reduced in amplitude by adaptation to a stationary grating. These properties suggest that P1 reflects the activity of a transient, motion-perception visual subsystem. Subsequent in latency to P1 was a negative peak labeled N2 which was largest at intermediate spatial frequencies, larger following pattern-onset than pattern-reversal stimulation, and reduced in amplitude by adaptation to a stationary grating. These properties suggest that N2 reflects the activity of a pattern-perception visual subsystem.