Children with autism spectrum disorder (ASD) tend to be less playful than their typically developing (TD) peers. Although playfulness is considered a personality characteristic, little is known about the stability of this trait in interactions with different caregivers. This study compared the playfulness of children with and without ASD in play interactions with their mothers at home and with their teachers at preschool. Twenty-nine children with ASD and 32 TD children (age 3-6), their mothers and teachers participated in the study. A significant difference was found between playfulness of children with and without ASD when playing with their mothers, but not when playing with their teachers. Additionally, while children with ASD tended to be more playful with their teachers, TD children were more playful with their mothers. The current study suggests that playfulness may be an adaptive trait, related not only to individual characteristics, but also to environmental ones. (author abstract)