This study was conducted to observe complications of the nervous system in chronic renal failure (CRF) and to observe the time of recovery of the nervous complications after successful renal transplantation. Median nerve somatosensory evoked potentials(MN-SEP), tibial nerve somatosensory evoked potentials(TN-SEP), brainstem auditory evoked potentials(BAEP) and visual evoked potentials (VEP) were recorded by using a Medelec ST10 Sensor EP apparatus before renal transplantation and subsequently 2, 4 and 12 weeks after renal transplantation in 40 CRF patients (32 men and 8 women). Results were then compared with normal data from age, sex and height matched controls. . At the same time of EP testing, BUN, serum creatinine, hemoglobin, hematocrit and parathyroid hormone of CRF patients were checked, and these changes were compared with the alterations of multimodal EP. In pre-renal transplantation states, the values of all of the absolute latencies and most d the interpeak latencies of MN-SEP,TN-SEP and BAEP were more prolonged than those of normal controls, but absolute latencies of VEP were not prolonged significantly. Multimodal EP responses except VEP showed improvement toward normal for 2 weeks, a steady state until 4 weeks, and then further improvement until 12 weeks after renal transplantation. In general, multimodal EP responses except BAEP showed more significant improvement in 12 weeks than did those of 2 weeks after renal transplantation MNSEP did not recover to normal control levels even by 12 weeks after renal transplantation, whereas some of the TN-SEP components had recovered to normal control levels in 2 weeks after renal transplantation, but VEP showed no significant alterations compared with normal controls before and after renal transplantation. In pre-renal transplantation states, most frequent abnormalities were found in MN-SEP (51.3%) whereas least frequent abnormalities were in VEP (5%). BAEP showed only peripheral nervous system dysfunction, whereas the other EP showed central and peripheral.