The study reported in this article used Fragile Families data to test a mediational model of the influences of nonresident black fathers' involvement with 492 low-income single mothers and their three-year-old children (time 3) on the mothers' psychological well-being and parenting adequacy and the children's socioemotional development at age 5 (time 5) as they prepared to enter elementary school. The findings generally replicated earlier research with a smaller sample. The results showed that nonresident biological fathers are important in the lives of young black children. The availability of social and instrumental support from fathers was associated with better psychological and parenting outcomes for mothers, which in turn predicted fewer child behavior problems at time 3. Fewer behavior problems at time 3 were associated with fewer such problems at time 5. The results provide significant support for interventions in programs aimed at reducing the adverse consequences of single parenting for young children in economically challenged black families.