Objective, quantitative measures of caregiver-child interaction during play are needed to complement caregiver or examiner ratings for clinical assessment and tracking intervention responses. In this exploratory study, we examined the feasibility of using automated video tracking, Noldus EthoVision XT, to measure 159 2-to-7-year-old autistic children's patterns of movement during play-based, caregiver-child interactions and examined their associations with standard clinical measures and human observational coding of caregiver-child joint engagement. Results revealed that autistic children who exhibited higher durations and velocity of movement were, on average, younger, had lower cognitive abilities, greater autism-related features, spent less time attending to the caregiver, and showed lower levels of joint engagement. After adjusting for age and nonverbal cognitive abilities, we found that children who remained in close proximity to their caregiver were more likely to engage in joint engagement that required support from the caregiver. These findings suggest that video tracking offers promise as a scalable, quantitative, and relevant measure of autism-related behaviors.