The main goal of environmental education is the development of environmental awareness, which is the basis for pro-environmental behavior. In order to determine the conditions which, favour the development of environmental awareness, a survey was conducted of students in the fourth grade of primary school, based on data from TIMSS 2019. The criterion variable was the score on the Environmental Awareness Scale, while the predictor variables included characteristics which vary at student, class, and school levels. Hierarchical linear modeling indicated the importance of variables at the individual level: home resources, literacy and numeracy readiness for school, confidence in science, usefulness of science lessons, and parent’s perceptions of their child’s school and expected student education level. None of the considered class and school level variables were significant predictors of environmental awareness. Between-school differences were fully explained by the final, retained model, but some variance (approx. 8%) between different classes remained unexplained by the considered predictor variables. We offer suggestions on how to increase the school’s contribution to the development of students’ environmental awareness through the application of effective pedagogy and school improvement. Further research is needed into the contribution of the educational environment.