This study examined associations between mother-infant nighttime interactions and mother-infant attachment when infants were 12 months old. Forty-four mother-infant pairs participated in this study. For three consecutive nights at home, babies were observed in their cribs using a digital video system. Mothers reported on their nighttime interactions with their babies using a self-report diary and completed a questionnaire regarding child temperament. Attachment was assessed in the Strange Situation (Ainsworth, Blehar, Waters, & Wall, 1978). Mothers of securely attached infants had nighttime interactions that were generally more consistent, sensitive and responsive than those of insecurely attached infants. Specifically, in secure dyads, mothers generally picked up and soothed infants when they fussed or cried after an awakening.