This study investigates predictors of environmental awareness among Spanish students participating in the 2006 Programme for International Student Assessment (PISA). The research focuses on understanding the influence of sociodemographic, cognitive, and non-cognitive factors on students’ environmental awareness. Using data from a representative sample of 19,604 Spanish 15-year-olds, collected by the OECD, the study employs regression analysis to identify significant predictors. The findings indicate that sociodemographic factors such as grade and socioeconomic status play crucial roles in predicting environmental awareness. Additionally, cognitive factors and non-cognitive factors significantly influence environmental awareness scores. The study highlights the importance of integrating science-related activities and fostering science self-efficacy to enhance students’ environmental awareness. These insights provide a foundation for educational practices and policies aimed at preparing students to effectively address sustainability challenges.