Objectives: Maternal posttraumatic stress disorder (PTSD) is a risk factor for negative child adjustment, but it is unclear whether this association is direct (e.g., a mother’s PTSD symptoms are observed, learned, and internalized by children which results in behavioral and emotional problems) or indirect, through parent-child relationship difficulties or parenting stress. We hypothesized that parenting stress and maternal emotional availability would exhibit indirect effects on relationships between maternal PTSD and children’s functioning. Method: Participants were 52 trauma-exposed mothers and their children (aged 7-12 years). Mothers completed measures of PTSD and parenting stress and reported on their children’s functioning. Emotional availability was assessed through observer-rated mother-child interactions. Results: Emotional availability was not related to PTSD or child outcomes. Parenting stress had a substantial indirect effect on the relationships between maternal PTSD and child emotion regulation, internalizing, and externalizing behaviors. Conclusions: Results highlight the need to target parenting stress in interventions with trauma-exposed families.