French studies on inequalities of access to higher education (HE) have focused either on the influence of students’ social background or on their school trajectories (Duru-Bellat, Kieffer 2008). While one statistical analysis found significant differences between students’ HE choices according to the secondary schools attended (Nakhili 2005), none has opened the “black box” of what goes on within schools. This was the aim of our ethnographic study of 4 secondary schools in the Parisian region. These schools were chosen according to various criteria: location (poor or rich areas) status (public or private), types of tracks provided (academic, technical, vocational) and students’ academic, social and ethnic profiles. The two-year fieldwork in each school included: observations of quarterly “class councils” and of all meetings and activities related to the transition to HE, interviews with students, teachers, headteachers, other school personnel and parents and the analysis of all relevant statistical and qualitative written data. Inspired by the work of McDonough (1997) and Reay et al. (2005), our theoretical framework combines closure theory (Parkin 1974), with a view to document traditional and new ways in which educational institutions contribute to the reproduction of inequalities (Bourdieu, Passeron 1977), and neo-institutionalist theories used to analyze the links between schools and higher education institutions (Hill 2008) and the recreation of low or high status educational tracks (Kingston and Lewis 1990). The presentation will focus on the ways in which schools’ external environments and internal characteristics influence school professionals’ conceptions of students’ futures and the preparation and advice they provide to encourage students’ access to and success in HE.