In this study, the sequential associations between child communication acts, including spontaneous communication (SC) and elicited communication (EC), and the types of verbal responses of Iranian mothers (follow-in nondirective, follow-in directive, and redirective responses) were compared between children with autism spectrum disorder (ASD) and young typically developing (TD) children. Participants were 29 children with ASD aged 3-6 years and 40 TD children aged 13-18 months, matched on expressive vocabulary. Using time-window sequential analysis, maternal verbal responses within a time interval of 3 sec following child communication were examined during 15 min of video-recorded mother-child free play interaction. Mothers in the two groups had broadly similar patterns of response to child communication acts, but some differences in responding to child EC. Across both groups, sequential associations were stronger for maternal follow-in nondirective responses to child SC than for this type of response to child EC, and were stronger for follow-in directive responses to child EC than for follow-in directive responses to child SC. Child EC and SC acts were less likely to be followed by redirective responses than other maternal responses, again across both groups. Finally, mothers of children with ASD were more likely than mothers of TD children to follow-in to child EC with both nondirective and directive responses. Our findings suggest that mothers of children with ASD synchronize their responses with their child’s SC acts to the same extent as mothers of TD children, and are more synchronous in responding to their child’s EC acts. LAY SUMMARY: This observational study examined how Iranian mothers verbally responded to their children’s communication acts, based on whether the children’s communication was spontaneous (unprompted) or elicited (prompted by the mother). Mothers of children with autism spectrum disorder or typical development responded to their children’s spontaneous communication acts in similar ways, but showed some differences in responding to children’s elicited communication. By prompting their children to communicate, mothers create opportunities to give additional verbal responses to their children, which may help to support children’s further language development.© 2020 International Society for Autism Research and Wiley Periodicals LLC.