In an attempt to develop objective criteria for the process of mother-child bonding, 18 premature infants with a birth weight of less than 1,501 gm were regularly observed alone and together with their mothers during each nursery visit and three home visits, one, two, and three months after discharge from the hospital. Results indicate that (1) mothers visit longer and increase their caretaking behaviors over visits and remain consistent in the rank order of their caretaking behaviors over time. (2) Caretaking behaviors are highly intercorrelated and mothers can be divided into those who show a consistently high, medium, and low amount of interaction with their infants. (3) Highly interacting mothers also visit and telephone the nursery more and stimulate their infants more at home. Mothers who stimulate their infants little in the nursery also visit and phone less and stimulate them little at home. (4) Infant behaviors showed that infants whose gestation was less than 29 weeks did not respond to any type of maternal stimulation. Infants whose gestation was more than 29 weeks, however, showed significantly more eye-openings when their mothers touched them.