It has been reported that frontal lobe structures are critical for the generation of P300 activity in the human event-related potential (ERP) evoked by novel events. In this study spatial-temporal dipole model analyses were employed to obtain further evidence on the temporal dynamics and the approximate location of neuronal activity involved in P300 generation for target and novel events. A triple dipole configuration was found to describe the scalp recorded P300 activity for novel and target events with less than 2.5% residual variance. For the novel, but not the target dipole configuration a frontally oriented dipole was obtained whose temporal activity function suggests that the brain areas involved in the processing of novel events are engaged about 70 ms earlier than those relevant for target processing.