Assessment of communication skills in children with autism spectrum disorder (ASD) is challenging in an unfamiliar clinical environment due to their limited verbal output and inadequate motivation to communicate. To analyze whether the communication sample recorded at clinic represents the child’s competence and performance, this study compared caregiver–child interaction in 24 to 48 months old children with ASD (n = 10, M = 38.2 months) at clinic and home. The 30-minute caregiver–child interaction at clinic and home was video recorded and analyzed for frequency of pragmatic acts (initiations and responses) and duration of joint engagement. Results indicated that children initiated and responded more at home than at clinic, whereas caregivers initiated and responded more at clinic. The study provides evidence that communication profile of children with ASD in multiple environments needs to be considered for obtaining representative and reliable communication sample for child-centered assessment and intervention.