Children's immediate aggressive responding to exposure to marital conflict was examined. Participants were 108 families with 8- to 16-year-old children (53 boys, 55 girls), with diary records of children's reactions to marital conflict in the home completed by 103 mothers (n = 578 records) and 95 fathers (n = 377 records) during a 15-day period. Child responses to analog presentations of marital conflict tactics were also obtained. Exposure to destructive conflict tactics and negative parental emotionality increased the likelihood of aggressive behavior in children when they witnessed marital conflict, whereas constructive conflict tactics and positive parental emotionality decreased the probability of aggression. Conflict topics presumed to be threatening to the child (child- or marital-related) also heightened the likelihood of aggression. Aggressive responding to conflict in both home and laboratory predicted externalizing behavior problems. Fathers' and mothers' separate diary reports, and child responses to analog presentation of conflict, provided generally consistent findings. An exposure hypothesis for marital conflict as an influence on child aggression is discussed.