Immigrant children in Germany are often referred to as being disadvantaged by the German educational system (Diefenbach 2007; Gogolin 2005; OECD 2006). Achieving significantly lower scores in international large-scale assessments as compared to their autochthonous peers, they are often labeled as a ‘at risk group’. The acquisition of ‘academic language proficiency’ has been identified as one crucial factor predicting a successful school career (Cummins 2000, Schleppegrell 2004). By instructing immigrant children purposefully in academic language, a reduction of this inequality in educational opportunities is intended. Based on data collected in a study evaluating additional courses offered to students of German ‘Hauptschule’, we intend to contribute to the question to what extent the mentioned ‘group at risk’ shows a delay in the acquisition of academic language proficiency (Knapp 1999) . We want to investigate factors enhancing the acquisition of academic language proficiency even under the special conditions of the ‘non-inclusive’ German Hauptschule. First results show, the mentioned delay can be identified only concerning first generation students, whereas second generation students perform as their autochthonous peers. A further finding suggests that family-literacy constitutes an important resource enhancing the acquisition of academic language proficiency especially with regard to first generation students.