Quality of mother-infant interaction and the impact on child development skills of premature and full-term children at 3 months of age Introduction:Face-to-face interactions allow for children to acquire experiences that will make it possible for them to communicate with their environment. Therefore, maternal sensitivity has been regarded as a crucial aspect in understanding the acquisition and development of skills related to child development. In this sense, selfregulation is developed through interactions with the environment, i.e. through responses to stimuli and learn-by-doing experiences. Preterm birth is regarded as a risk factor for child development. Moreover, early delivery can be described as a traumatic event for the family, which may result in changes to parenting patterns and to levels of maternal sensitivity. Objective: To assess the quality of the mother-baby dyad and the self-regulation infantile processes and their influence on the development of skills gross motor, fine-adaptative motor, personal-social and language of threemonth-old preterm and term infants children. Materials and methods: ethical standards were fulfilled (CAAE: 90550318.4.0000.5417). We evaluated 54 dyads.They were split in two groups: 21 preterm dyads (EG) and 33 term infants children. The instruments used were: maternal interview, "Critério de Classificação Econômica Brasil", Face-to-Face Still-Face, Child-Adult Relationship Experimental Index and Screnning Denver Development Test-II. Statistic methods were used to analyze the variables: T-Test, Independent Samples T-Test, Chi-Square test Pearson, Pearson Correlation, ANOVA and Tukey Post Hoc Test. Results: 47,6% of the EG and 45,5%of the CG reported that their pregnancy had been planned, as revealed by the interviews. On the other hand, 71,4% of the EG and 45,5% of the CG reported that their pregnancies had been desired. No statistically significant differences were found between the two groups and the socially negative self-regulation orientation prevailed in both groups. No statistically significant differences as regards the interactions between mother and babies were found, either. We found a significant negative correlation between maternal sensitivity and child binge. We have also found a statistically significant positive correlation between maternal sensitivity and child cooperation. By contrasting the Care-Index to the self-regulation standards we found that maternal sensitivity and the self-comfort rate were greater in the positive social orientation group. In the same vein, maternal control was less significant within this group. Statistically significant differences were found when contrasting the performances of the EG to the ones of the CG as regards personal-social and language skills. The 5 th Minute Apgar and gestational age were correlated with personal-social and language skills. Birth weight was correlated with language area.