Mottron and colleagues found that individuals with autism were less affected by geometric impossibility than comparison participants on a copying task. The current experiment sought to determine whether a local perceptual style could account for this. Participants with and without autism copied possible and impossible geometric figures. Geometric impossibility had a larger effect on drawing time for comparison participants than for those with autism. However, participants with autism did not use more localized drawing strategies. Strength of impossibility effect was associated with a global strategy amongst comparison participants but this relationship was not found amongst participants with autism. The findings suggest that differences in high-level conceptual processing may account for group differences in effects of impossibility. (Contains 3 tables and 4 figures.)