Posttraumatic stress disorder (PTSD) symptoms are associated with disruptions in both couple functioning and parenting, and limited research suggests that, among military couples, perceptions of couple functioning and parenting stress are a function of both one’s own and one’s partner’s mental health symptoms. However, this work has not been generalized to civilian couples, and little is known about the associations between PTSD symptoms and family adjustment in specific family developmental contexts. We examined PTSD symptoms’ associations with perceived couple functioning and parenting stress within a dyadic context in civilian couples who had participated in a randomized controlled trial of a universal, couple-based transition to parenthood program and at least one member of the couple reported having experienced a Criterion A1 traumatic event. Results of actor–partner interdependence models revealed that parents’ own and partners’ PTSD symptoms were negatively associated with perceived couple functioning; contrary to expectation, the association of partners’ PTSD symptoms with perceived couple functioning was strongest among men who received the intervention. A parent’s own PTSD symptoms were positively associated with parenting stress for both men and women and were unexpectedly strongest for men who received the intervention. Partner PTSD symptoms were also positively associated with increased parenting stress for both men and women. Findings support a dyadic conceptualization of the associations between spouses’ PTSD symptoms and family outcomes during the transition to parenthood and suggest that participating in a couple-based, psychoeducational program during this phase in the family life cycle may be particularly salient for men.