A method for recording pattern reversal evoked potentials (PREPs) from awake restrained rats has been developed. The procedure of Onofrj et al. was modified to eliminate the need for anesthetic, thereby avoiding possible interactions of the anesthetic with other manipulations of interest. Rats were restrained in a harness and placed in front of a pattern generating TV screen displaying a black and white alternating square wave grating. Using various stimulation and recording parameters, normative data are presented from 141 adult male Long-Evans hooded and 11 adult male Sprague-Dawley albino rats. Reliable waveforms were recorded with five identifiable peaks. The labels and mean latencies of these peaks in hooded rats were: N1, 47.3 msec; P1, 65.7 msec; N2, 83.3 msec; P2, 94.4 msec; and N3, 129.9 msec. Spatial acuity functions generated with PREPs gave acuity estimates which corresponded closely to values determined behaviorally for hooded and albino rats.