Background: Children with an autism spectrum disorder (ASD) are known to have an atypical visual perception, with deficits in automatic Gestalt formation and an enhanced processing of visual details. In addition, they are sometimes found to have difficulties in emotion processing. Methods: In three experiments, we investigated whether 7-to-11-year old children with ASD were showing superiorities or deficits in matching tasks that required focusing on faces with an emotional expression. Throughout these experiments, we increased the complexity of the stimuli and tasks demands. Results and conclusions: In matching faces with emotional expressions, children with ASD were not able to show superior processing of details in any of the three experiments. They were able to compensate their inferior processing of emotions in some of the experiments (e.g., by using a slower, more sequential processing style). However, when stimulus complexity (e.g., dynamic facial expressions) or task demands (e.g., extracting and remembering the relevant stimulus dimension) increased, they were no longer able to do so, and they did show performance deficits. (Contains 10 figures and 4 tables.)