The aim of this study was to assess the mother-pre term baby interactions and the signals of the affective bond development in the hospital environment. The sample comprehends nine babies, of both sexes, born between twenty-eight and thirty-six weeks of gestational age, free of complications such as syndromes or malformations and their respective mothers. The instruments used were the medical records and the protocols of the baby's clinical history and of the mother-baby's observations. The data was analyzed in terms of percentage of occurrences and regarding the quantitative analysis of these activities. The results indicated that the exchanges in the interactions between mother and baby were adequate in 55,5% of the corporal and vocal categories and 44,4% of the visual and facial categories. These results suggest that in the exchanges between the baby and the carer, in his/her posture, in the language modes, in the visual contact and in the facial expressions that the behavior and responses in the baby and his/her parents are reflected.