Long-term EEG monitoring (LTM) with several electrodes could be a useful tool for surveillance of the brain during the first critical days of life. This study aimed to assess the feasibility of multichannel LTM for automated analysis of EEG activity from d 1 to 3 using eight electrodes. Premature infants (GA Ͻ31 wk; n ϭ 48) were continuously monitored for 3 d. EEG monitoring for a total of 3257 h was successfully performed. Total absolute band power (tABP) was calculated per second. Artifacts were removed visually or by an algorithm removing the highest 5, 10, 15, and 20% tABPs. NS difference was found between the trends of visually edited and 5% mathematically trimmed data. Two groups were compared (24 Յ GA Ͻ 28 wk and 28 Յ GA Ͻ 31 wk) using the median of tABP for all frequency bands per day. The results showed that tABP differed between groups. The changes of tABP d 1-3 were equal in both groups. Automatically assessed LTM confirms that the EEG activity depends on GA. However, it reveals that the early changes (d 1-3) are independent of GA. The study demonstrates the feasibility of multichannel LTM and the possibility of developing automated EEG analyses. (Pediatr Res 69: 413-417, 2011)