Little is known about the impact on the development of the baby of the environmental factors and cotidal tasks to which the teenager mother is exposed. This study therefore proposes to identify the associations and predictors of motor and cognitive development of babies children of adolescent and adult mothers. 40 babies aged 0 to 18 months were evaluated, with 20 babies in each group – adolescent and adult mothers. The evaluations were through Alberta Motor Infant Scale and Bayley Scale of Infant Development; Assignments in the Home Enviroment for Motor Development, Knowledge of Infant Development and Daily Activities of Infant. Strong association between motricity and cognition (r² = 0,88) was observed in both groups studied. Among babies of teenage mothers, paternal age, home space, mother not working away from home, parents’ schooling, amount of toys and adults at home, parental practices and parents’ knowledge have been shown to predict motor development. For cognitive development, predictive fathers were shown to live together, the amount of rooms in the home and parental practices. In the group of babies of adult mothers, cognitive development, cesarian childbirth, fathers die together, amount of rooms in the house, and parental practices have been predictive of motor development. As predictors of cognitive development, engine development, number of days in UTI, number of quarters at home and parental practice remained in the regression model. The interdependence between cognition and motricity, family and residence characteristics, and parental practices were the main determinants of the infant’s trajectory.