The present study examined whether fundamental sensory functions such as temporal processing and multisensory integration are related to autistic traits in the general population. Both a narrower temporal window (TW) for simultaneous perception, as measured by a temporal order judgement task, and a reduced ability to engage in multisensory integration during the sound-induced flash illusion task were related to higher levels of autistic traits. Additionally, a narrow TW is associated with high levels of autistic traits due to a deficiency in multisensory integration. Taken together, these findings suggest that alterations in fundamental functions produce a cascading effect on higher-order social and cognitive functions, such as those experienced by people with autism spectrum disorder.