The aim of this study was to examine the determinants and correlates of school achievement, that is, to investigate the possibility of predicting school success based on demographic characteristics, personal and social incentives and professional aspirations. As a measure of school achievement, we used composite scores across several variables (objective and subjective indicators of school achievement) designed for the purposes of this study. The study included 937 graduate students from Zagreb and its surrounding area. Data was collected on-line as part of the research project “Vocational Development in Adolescence: Setting the Adolescent Career Transition Model”. The results partially confirmed our expectations. The high school students only somewhat differed in their school achievement with regard to demographic characteristics. Girls achieved better school achievement than boys. Also, high school students exhibited better achievement than students of secondary vocational schools. Nevertheless, it is not unambiguously confirmed that the high school students of different socioeconomic status differ significantly by success at school. School satisfaction showed the highest correlation with school achievement, meaning that, as student satisfaction increased, so did their school achievement. The next highest correlations were those of school achievement with educational aspirations and self-evaluation. Students with higher educational inspirations and higher self-evaluation achieve higher academic achievement. Results of hierarchical regression analysis showed that, on the basis of three blocks of predictors (demographic characteristics, personal and social incentives, professional aspirations), it was possible to explain 17% of the variance of school achievement. The best predictors of school achievement within the model were school satisfaction and gender, followed by educational aspirations.