This research examined how participation in certain religious network can be a relevant factor to ensure access and retention in school units with good results in external evaluations. The goals were to identify possible influences of religious networks into the familys strategies of choosing the educational establishment and to verify in which level the family practices related to a successful education of the children are related to the participation of the respective families in these networks. Quantitative analysis was performed based on national data of public domain provided every two years about school performance on the municipal schools, in particular those of a very diverse set of neighborhoods and schools in the northern and southern areas of the city of Rio de Janeiro. Since then, four schools, which offer the 5th year of elementary school, were selected according to their performance (results in IDEB). A profile of these school units was charted through interviews with administrators and teachers in order to complement the quantitative research with an analysis of the perceptions of school stakeholders on this issue. From interviews with the students families and data records of the school enrollment, provided by the Municipal Secretariat of Education of the City of Rio de Janeiro, it was possible to build up a profile of the families whose children are attended by these schools, investigating possible correlations among school flow, family practices and religious affiliation. The consolidation of the data obtained in these studied schools indicated that the concentration of students in the same religion in units with good results in external evaluations is strongly associated with socioeconomic status and type of family arrangement.