To evaluate central nervous system functioning involvement in nocturnal enuresis, P300 and N200 event-related brain potentials and brainstem auditory-evoked potentials (BAER) were assessed in a group of 35 enuretic boys aged 7-9 years. The measurements of enuretic group were compared to those of age and sex matched non-enuretics. P300 latency in the enuretic group was significantly longer than in non-enurefic group (420 ms at parietal scalp (Pz), 414 ms at central scalp (Cz) versus 386 ins at Pz, 376 ms at Cz; P < 0.01 and P < 0.01, respectively). Both enuretic and non-enuretic subjects were divided into three subgroups his age. There was no significant difference in terms of both P300 amplitude and N200 latency and N200 amplitude between non-enuretic age subgroups. But, P300 latency over central scalp in 8 years old non-enuretic subgroup was significantly longer than in 9 years old non-enuretic subgroup (P < 0.01). No significant difference was found in latency and amplitude of P300 and N200 latency between enuretic subgroups. However, N200 amplitude at Cz in 8 years old enuretic subgroup was significantly lower than both in 7 years old enuretic subgroup and in 9 years old enuretic subgroup (P < 0.01 and P < 0.01, respectively). There were significant topographical differences in latency and amplitude of P300 and in N200 latency in enuretic age subgroups, only. There was no significant difference in interpeak latencies I-III, I-V and III-V and wave latencies I, III and V of BAERs between enuretic group and non-enuretic subgroup. Longer interpeak and wave latencies of BAERs were found both in 8 years old enuretic subgroup and 8 years old non-enuretic subgroup. Conclusion: Longer P300 latency in primer enuretics compare to non-enuretics is an evidence of a maturational delay of central nervous system functioning. (C) 2002 Elsevier Science B.V. All rights reserved.