A large portion of our experience combines information from multiple sensory modalities. The ability to process an abundance of information, and to identify the relevant pieces is highly dependent on mechanisms of multisensory integration (MSI) (Stein & Meredith, 1993). This dissertation focused on audiovisual (AV) MSI, in which sensory information is combined from the auditory and visual modalities to create one, coherent, multisensory percept. While simple stimuli such as flashes and beeps have formed the basis of many past experiments, more recently, studies have started advocating for the use of more naturalistic stimuli, which mimic the complexities present in the environment (Stevenson & Wallace, 2013). Studies have shown that MSI improves performance on a range of tasks from basic perceptual tasks to cognitive tasks involving learning (Newell, Mamassian, & Alais, 2010; Shams & Seitz, 2008). Although past studies have linked MSI and mnemonic processes, studies of MSI and working memory remain sparse. In a series of studies, this dissertation aimed to answer the following outstanding questions: Do multisensory stimuli provide a benefit for working memory processing? Are the auditory and visual modalities linked differently based on stimulus properties? What are the effects of crossmodal congruency on MSI and working memory? To address these questions, we tested the impact of simple and complex multisensory stimuli on working memory in adults using a change detection paradigm. We found enhancements in visual and auditory working memory when presented with multisensory stimuli. However, the attentional demands of the task, complexity of stimuli presented, crossmodal congruency, type of working memory (visual or auditory) tested, and memory load presented mediate the nature of this enhancement. The findings in this thesis make a contribution to the growing scientific literature in the domains of multisensory integration and memory, and also have implications for educational practices.