Summary Background In developed countries high socioeconomic status (SES) is associated with lower body mass index (BMI) and greater height compared with low SES. Aim To investigate differences in BMI/height in adolescent students from two different school types with divergent SES backgrounds. Methods A total of 4579 students (2313 female), aged 11–16 years, attending either low SES vocation-directed secondary schools (VSS) or high SES secondary academic schools (AHS) were compared. Potential differences were investigated using ANCOVA models including sex, school type, geographical region and degree of urbanicity. Results At all ages between 11 and 16 years the BMI of students attending VSS was significantly higher than that of students attending AHS (mean +0.87kg/m2). The AHS students were on average taller (mean +0.93cm; p100,000 (p