Attention has been shown to strongly interact with both unisensory and multisensory processes. An emerging question of interest is whether unattended multisensory stimuli can be integrated in order to influence behavioral and/or perceptual performance. To investigate this question, we designed a paradigm to examine the impact of unattended information both within and across sensory modalities on a visual pattern completion task. Participants were asked to view a sequential pattern of shapes and to predict the next shape in the sequence. During the “learning� phase, the shapes were presented at fixation and were paired with an unattended visual (peripherally-presented color flash) and auditory (tone) stimulus. Each unattended stimulus was linked with a specific shape, and subjects were instructed to actively ignore them. During the test phase either the visual, auditory, or paired visual-auditory stimuli were presented, and subjects had to predict the next shape in the sequence. Participants’ accuracy on each of the different trial types (including incongruent pairings) was assessed. Unattended unisensory stimuli and unattended congruent multisensory stimuli failed to significantly affect performance. In contrast, unattended incongruent multisensory stimuli significantly impaired performance, illustrating the capacity of unattended multisensory cues to interact with and shape behavior.