Long Island University will investigate the effects of group parent-training interventions with fathers on the prevention and treatment of externalizing problems in Head Start children aged 3 to 5. Participants will be 60 father-mother-child triads. Fathers will either be married to and residing with the mother, or will be unmarried but residing with the mother for at least six months. Fathers are not required to be biological but must be integrally involved in the child's well-being. After a 3-week pretest screening, fathers will be randomly assigned to either a 12-week parent-training group or a control group. The training will consist of a videotape program showing desirable and undesirable parenting behaviors, as well as discussions and role plays led by therapists. Topics will include positive parenting interactions, handling misbehavior, and problem solving. The pre-post-intervention design will assess the parent-training group's effects on parenting behaviors, child care responsibility, marital/relationship satisfaction, and child behavior. The researchers hypothesize that those fathers participating in the intervention will take on more child rearing responsibilities, increase their use of positive parenting behaviors, use more effective discipline techniques, and experience higher rates of marital or relationship satisfaction.