We examined developmental aspects of the ability to monitor the temporal context of an item's previous occurrence while event-related potentials (ERPs) were recorded. In a continuous recognition task, children between 10 and 12 years and young adults watched a stream of pictures repeated with a lag of 10-15 intervening items and indicated recurrences. In a second run, these already familiar pictures were repeated as non-targets along with new pictures, while subjects were instructed to indicate only recurrences "within" the run. Young adults were able to maintain high performance levels in both tasks, whereas children had longer response times and committed a large number of false alarms to non-targets. ERPs in both age groups showed similar parietal old/new effects for target repetitions within runs. In addition, adults' ERPs showed similar old/new effects at frontal electrodes for repetitions and non-targets, presumably reflecting assessments of familiarity, whereas for children repeated relative to first presentations were associated with more negative-going waveforms at anterior frontal recording sites. Together, these results suggest a continuing maturation of the brain networks assessing novelty or familiarity. Recollection as indexed by parietal old/new effects appeared similar between young adults and children, but the development of controlled episodic retrieval, resulting in recollection of non-target information, appears to continue well into adolescence.