The latency and amplitude of the P3b component of event-related potentials (ERPs) have been related to behavioural performance on several attention and memory tasks in adult populations. However, the extent to which these results apply to children is unknown. This study examined the neurobehavioral correlates of the P3b component in a longitudinal sample of school-age children from Arctic Québec. Children ( N = 110; mean age = 11.3 years) were assessed on an ERP auditory oddball paradigm and a neurobehavioral evaluation targeting several aspects of cognition, including the Stewart Extended Continuous Performance Test (E-CPT), California Verbal Learning Test (CVLT), Stroop Color-Word Interference Test, and five subtests from the Wechsler Intelligence Scale for Children-Fourth edition (WISC-IV). P3b latency was positively related to reaction time measures and negatively associated with performance on the WISC-IV Digit Span Forward subtest. Amplitude of the P3b was associated with shorter completion time on the Stroop test and better delayed recognition memory performance among children who did not use semantic strategies on the CVLT. Profile analyses revealed no difference in scalp distribution of the P3b according to performance on these tests. The results are consistent with previous studies with older participants and suggest that, despite age-related differences in waveform and scalp distribution, the P3b component relates to similar neurocognitive processes in children and adults.