This study's purpose was to examine whether child characteristics, child illness severity, maternal characteristics, maternal psychological well-being, and paternal support influenced interactions between 108 premature infants and their mothers. Mothers with singletons or more infant illness stress showed more positive involvement. Mothers with less infant illness stress, less education, or less participation in caregiving by fathers showed more negative control. First-time mothers and mothers of singletons provided more developmental stimulation. Children of younger and White mothers showed more social behaviors. Less maternal education and shorter period of mechanical ventilation were associated with greater developmental maturity. Greater maternal worry was related to more child irritability. These findings are consistent with the developmental science view that the mother-premature relationship is a complex, reciprocal process.