Relations of duration and developmental timing of poverty to children's development from birth to age 9 were examined by comparing children from families who were never poor, poor only during the child's infancy (0-3 years of age), poor only after infancy (4-9 years of age), and chronically poor. Chronically poor families provided lower quality childrearing environments, and children in these families showed lower cognitive performance and more behavior problems than did other children. Any experience of poverty was associated with less favorable family situations and child outcomes than never being poor. Being poor later tended to be more detrimental than early poverty. Mediational analyses indicated that poverty was linked to child outcomes in part through less positive parenting.