In the years when children go to elementary school (6 -12 years old), they face tasks related to their development, academic performance and interpersonal competence. Children's performance in these tasks is influenced by the interaction between the child's personal characteristics and the environment in which the child lives. Those who start elementary school with a richer repertoire developed previously are supposed to have a better performance. They tend to present healthier and more promising development. There are some studies about the impact of kindergarten (K) experience on the child's future academic life. The child's performance and the quality of its relationship with schoolmates and teacher at that moment predict its academic progress, as well as self-adjustment in the following years. This study aims to investigate which personal and environmental variables may work as predictors of children's academic performance and interpersonal competence, by analyzing how the exposure to K influences in the performance of developmental tasks typical of that phase. The children's personal characteristics investigated were: cognitive potential, social skills, and problem behavior. The environmental factors investigated were: school stress, family support in the child's school life, and the child's attendance to K. A group of 336 second-grade elementary students from public schools in a city in the inland of the State of São Paulo and their parents/guardians and teachers participated in this study. The children were assesssed with Raven's Progressive Matrices, the School Hassles Inventory, the School Achievement Test, Sociometric Interview, and pedagogical evaluation. Parents/guardians answered the Brazilian Social-economic Criterion; the teachers answered the Scale of Participation of an Adult Family Member and to the Social Skills Rating System -SSRS-BR, teacher form. Regression analysis was used for prediction of academic performance and interpersonal competence with the child's and its environmental variables, as well as socialeconomic indicators. The non-parametric method Kruskal-Wallis test was used in order to compare groups. Ninety-five out of 336 children were selected and compared as for the time of attendance/exposure to K: 32 did not attend K; 31 had one year of K; 32 had two years of K. These 3 groups were balanced social-economically and as for the family's breadwinner's schooling. Results show that the personal and environmental characteristics to predict academic performance are: social skills related to responsibility and cooperation, cognitive potential, exposure to K environment, exposure to and impact of school hassles, family participation in the child's school life, social-economic level, and family's breadwinner's schooling. The predictors associated to interpersonal competence were the social skill of selfdefense and peer cooperation, problem behavior, and family participation in the child's school life. By comparison, K attendance has proven to have important influence, since children with...