The effect of focal application of laser energy on the modification of somatosensory evoked potentials (SEPs) was studied in sensory cortical fields of the rat. This article describes the methodological set-up for recording of SEPs and for determining location and size of the laser-induced lesion. The results show that both the size of the lesion of the somatosensory cortex, and the suppression and time of recovery of cortical SEPs varied depending on the laser energy dose. It remains to be analyzed by further experiments if the recovery of SEPs is due to a transient dysfunction of the somatosensory cortex or if it reflects cortical plasticity.