Exposure to intimate partner violence (IPV) is associated with children's internalizing and externalizing problems. IPV is thought to impair mothers' ability to scaffold young children's emotion regulation through coregulated interactions. Mother-child language style matching (LSM) is an index of coregulation that has yet to be examined in IPV-exposed samples. We hypothesized that LSM would mediate the association between IPV and children's behavioral problems. Participants were 194 mother-child dyads. IPV was assessed annually when children were ages 1-4. LSM was derived from speech during a free-play interaction at age 4, and children's behavior problems were assessed concurrently and again at age 10. Chronic IPV exposure in early life was associated with lower levels of mother-child LSM. LSM also mediated the association between IPV and later internalizing problems. These findings provide evidence that mother-child LSM may be a useful index of parent-child interaction quality in the context of IPV.