Introduction of rooming-in at the study site provided an opportunity to examine the impact of rooming-in on maternal attachment behaviors. Maternal attachment scores for 80 mothers who received rooming-in were compared to 72 mothers who delivered before rooming-in and 35 mothers who requested but did not receive rooming-in. All subjects were medically indigent primiparas with no intrapartum or postpartum complications and term healthy infants. The groups were not significantly different in maternal age, race, or ethnicity. Maternal attachment behaviors were recorded during an infant feeding. Rooming-in mothers had significantly higher maternal attachment scores than both control groups. Rooming-in had an independent effect on maternal attachment after the effects of maternal age, episiotomy or lacerations, epidural anesthesia, infant contact at delivery, and time of feeding observation had been accounted for. Of these prior factors, only maternal age had a significant impact on rooming-in. These results suggest that rooming-in helps primiparas to form early attachments to their babies, and that the impact of rooming-in cannot be explained by the mother's motivation for rooming-in. It is important to provide close contact with the infant during the early postpartum, especially for adolescents who may be at higher than average risk of mothering inadequacies.