Background: We assessed motion processing in a group of high functioning children with autism and a group of typically developing children, using a coherent motion detection task. Method: Twenty-five children with autism (mean age 11 years, 8 months) and 22 typically developing children matched for non-verbal mental ability and chronological age were required to detect the direction of moving dots in a random dot kinematogram. Results: The group of children with autism showed significantly higher motion coherence thresholds than the typically developing children (i.e., they showed an impaired ability to detect coherent motion). Conclusions: This finding suggests that some individuals with autism may show impairments in low-level visual processing – specifically in the magnocellular visual pathway. The findings are discussed in terms of implications for higher-level cognitive theories of autism, and the suggestion is made that more work needs to be carried out to further investigate low-level visual processing in autism.