This article reports on a study regarding the school-identification of 1819 first-year students in secondary vocational education. We measured the school-identification of these adolescents and used the perspective of self-regulation to define three blocks of potential determinants, including the students' personal goals (1) their appraisals of the school and classroom (2), and their peer- and home-identities (3). One other block included students' personal characteristics, such as general ability (i.e., course-level) and gender (4). In a two-wave regression procedure we investigated the contributions of the four blocks of potential determinants in explaining students' school-identification. The first wave showed three key-determinants, including students' appraisals of teacher-expectation and course-utility and the extent to which they felt alienated from their school. Of secondary importance were students' relational identities, with peer-identity being more important than home-identity. Personal goals were the least important determinants. The second wave showed how the key-determinants were explained by the students' appraisals of mutual-support, and involvement, fairness, humour, learning-support, reward and personal respect of their teachers. Elaborate interpretations of the results are provided in the discussion. (Contains 4 tables and 1 figure.)