<p>The future generation needs to develop an awareness and understanding of harmful ecological threats to make decisions and take actions to mitigate their impact. This study examines the environmental knowledge, awareness, and behavioral aspects of students (specifically of class 10 and 12) in both private and government high schools across all education boards in a representative city (Kolkata) in India. The research work involves the collection of 200 students’ responses using a 5-point Likert scale questionnaire from high schools belonging to three major accredited boards in Kolkata. The Statistical Package for the Social Sciences (SPSS, version 26) software was used to analyze the data. A total of 200 high school students from Class 10 and 12 were selected from 6 CBSE (Central Board of Secondary Education), 6 ICSE (Indian Certificate of Secondary Education) and 8 WB (West Bengal Board of Secondary Education) board accredited high schools using the stratified sampling method. The findings reveal that class 10 and 12 students across all nationally accredited boards have significant moderate positive correlations existing between their environmental awareness and behavioral patterns. Furthermore, class 12 students from the ICSE board scored the highest in terms of environmental behavioral patterns. The intention and attitude of the students were significant positive predictors of students’ environmental awareness, while the type of education board, intention, and attitude were significant positive predictors of students’ environmental behavioral patterns. The study accentuates the fact that enhancing environmental education by incorporating more action-based learning into the curriculum for high school students across all boards, while simultaneously supporting these efforts with strong institutional programmes will strengthen students’ awareness and behavioral patterns in support of environmental sustainability.</p>