Although it is often assumed that memory of episodic associations requires recollection, it has been suggested that when stimuli are experienced as a unit, earlier memory processes might contribute to their subsequent associative recognition. We investigated the effects of associative relations and perceptual domain during episodic encoding on retrieval of associative information. During study, participants encoded compound and non-compound words-pairs, presented either to the same sensory modality (visual presentation) or to different sensory modalities (audio-visual presentation). At test, they discriminated between old, rearranged, and new pairs while event related potentials (ERPs) were recorded. In an early ERP component, differences related to associative memory only emerged for compounds, regardless their encoding modality. These findings indicate that episodic retrieval of compound words can be supported by early-onset recognition processes, regardless of whether both words were presented to the same or different sensory modalities.