The dissociability of novelty detection in relational (RM) and non-relational memory (NRM) is currently under debate. To further address the time courses and underlying brain correlates of novelty detection, event-related potentials (ERPs) were analysed for encoding and retrieval on three memory tasks in healthy subjects. Spatial and non-spatial RM as well as NRM were assessed separately. The ERPs related to RM and NRM were dissociable for hits and correct rejections in an early and late time window. An early old/new effect was observed for NRM. A late old/new effect replicated the frequently reported recollection-associated old/new effect in terms of direction and amplitudes. Four different novelty types (spatial relational, non-spatial relational, horizontal non-relational and inverted non-relational) were examined. The P3a related to novelty detection differed in horizontal vs. inverted distractors in NRM, but not in spatial vs. non-spatial RM. ERPs for repetition detection (hits during retrieval) and also for subsequent hits (encoding phase) differed between RM and NRM. These findings are discussed in relation to potential brain correlates in RM and NRM during encoding and retrieval.