The incidence of child abuse and neglect resulting in validated case reports to the American Humane Association in 1976 was determined in relation to household composition, family income and age of the victim. Abuse and neglect were both maximal in father-only homes and minimal in two-natural-parent homes. Mother-only households exceed those with one natural and one step-parent in neglect incidence, but the reverse is true for abuse incidence. Poverty is more strongly associated with neglect risk than with abuse risk, and probably cannot account for the high risks of abuse and neglect in father-only and step-parent families. Evidence that the presence of an unrelated adult filling a parental role exacerbates the risk of physical abuse is presented and discussed.