Objectives: The aim of the study is to distinguish between perceptuomotor and cognitive inflexibility as the source of set-switching difficulties in children with autism spectrum disorder (ASD). Methods: Seventeen adolescents with ASD and 17 neurotypical controls were presented with a computerized sequencing game using colored shapes. The sequence required a shift in perceptuomotor responding that could also be represented at a conceptual level. Measures of perceptuomotor inflexibility were based on errors and response times specifically on the critical switch item in the sequence. The task included three transfer phases in which the same rule was to be applied to new shapes and colors. Higher-order rule conceptualization was operationalized as the ability to abstract the switching rule and apply it across these phases. Results: Participants with ASD showed predicted difficulties on the perceptuomotor shift, but no deficit on the transfer phases. Conclusions: The study indicates a problem with perceptuomotor inflexibility in ASD that can explain why 'extra-dimensional' shifting is sometimes reported as problematic in this group. Implications for difficulties in more real-world contexts are discussed.