Tackling early leaving from education and training (ELET) is one of the main education policy targets of the European Union and many of its member states. This paper offers new insights on this issue by studying how so-called at-risk students develop their educational trajectory by embedding their attitudes towards and engagement in schooling within the various support networks they navigate. We argue that the concept of school engagement, operationalized within the broader theoretical framework of the self-system model of motivational development, is crucial for better understanding ELET. The structural equation modelling is based upon survey data from 1401 students in grade 10 and 12 of vocational tracks across 26 different urban school locations in Flanders, Belgium. The results show that parental, peer and in particular teacher support directly and indirectly strengthen students' academic and behavioural engagement. We argue that universal and targeted support by educators can positively impact pro-school attitudes and school engagement of so-called at-risk students and may be one of the most important strategies in addressing ELET.