[en] Children with autism spectrum disorder (ASD) have more emotional difficulties than typically developing (TD) children. Of all the factors that impact children’s emotional development, parents, and the way they interact with their children, are of crucial importance. The present study compared the amount of parent-child interactions among 35 dyads of parents and their children with ASD and 41 dyads of parents and their TD children, aged between 3 and 13 years, during a frustration-eliciting situation. We further examined whether children’s alexithymia is linked to parent-child interactions and whether parent-child interactions are linked to children’s emotional difficulties. We found that parents of children with ASD interacted significantly less with their children than parents of TD children. This reduced interaction was better explained by children’s alexithymia than by children’s ASD diagnosis. Finally, parent-child interaction mediated the relationship between children’s ASD diagnosis and children’s emotion regulation ability, as well as some aspects of children’s emotional reactivity but only if not accounting for children’s alexithymia levels. Our results demonstrate the determinant role children’s alexithymia plays on parent-child interactions and on how these interactions are linked to children’s difficulties in emotion regulation and emotional reactivity. Results are discussed in light of how parent-child interactions and the emotional ability of children with ASD can be improved by targeting children’s alexithymia.