Background: Studies of families of asthmatic children indicate associations between psychological factors and asthma symptoms. Objective: We investigated relations between psychosocial factors and the development of respiratory symptoms within a large prospective cohort study. Methods: The children were prenatally assigned to high, medium, or low risk for asthma development on the basis of parental atopy and family history of allergic disease. When the children were 3 years of age, parents completed the Eyberg Child Behavior Inventory (ECBI), Family Relationships Index (FRI), Hospital Anxiety and Depression Scale (HAD), and General Health Questionnaire (GHQ). Results: Data from 663 participants were analyzed. ECBI intensity scores were significantly higher for children with parentally reported respiratory symptoms. Symptomatic low-risk children (both parents nonatopic, no family history of allergic disease) were particularly likely to have elevated behavior problem ratings. None of the other family psychosocial variables showed this pattern. Child behavior problems were, however, significantly positively correlated with the other family psychosocial variables. Logistic regression indicated that behavior problem scores were associated with 3 or more attacks of wheeze (P = .03, OR = 1.023), irrespective of risk group. Conclusions: Children at 3 years of age with symptoms suggestive of asthma are at elevated risk of behavior problems. Children from families without a history of asthma and allergic diseases may be particularly vulnerable to behavioral disturbance. Families may benefit from additional advice on management of their child's behavior, particularly if parents do not have the experience of having the illness themselves.