This study sought to describe fathers' participation in a statewide home-visiting program to prevent child abuse and to assess program impact on their parenting. This randomized trial followed 643 at-risk families for 3 years. Data were collected through program record review, staff surveys, and annual maternal interviews. Participation in visits varied by the parents' relationship and paternal employment, violence, and heavy drinking at baseline. Overall, the program had no apparent impact on fathers' accessibility to the child, engagement in parenting activities, and sharing of responsibility for the child's welfare. The program promoted parenting involvement for nonviolent fathers in couples who lived together but also for violent fathers in couples with little contact at baseline; it decreased the father's accessibility to the child in couples who lived apart but saw each other frequently at baseline. Infrequent participation in visits and differential program impact on violent versus nonviolent fathers demonstrate the need to consider family context in developing, implementing, and studying home-visiting models.