This study evaluates the efficacy of an early intervention program targeting African American mothers and their premature, low birth weight infants at 3 to 4 months' corrected age from four neonatal intensive care units, 173 families are recruited (84 intervention, 89 control). The 8-session, 20-week intervention consists of a psychoeducational video, serial administrations of the Brazelton Neonatal Behavioral Assessment Scale, and maternally administered infant massage. At postintervention, intervention mothers have higher maternal self-efficacy than control. Extremely low birth weight (ELBW) intervention infants have significantly higher Bayley Mental Development Index (MDI) scores than ELBW control infants, but no intervention effects are observed among heavier preterm infants. Among infants of families living above federally established poverty thresholds, intervention infants have higher MDI scores than control infants. No intervention effects were found for infants of families living in poverty. Findings emphasize the importance of considering meaningful moderators in evaluations of early intervention effects. (Contains 2 tables.)