Purpose: Through the application of the theory of planned behavior (TPB), this study aims to explore the main determinants of higher education students' pro-environmental behavior. Design/methodology/approach: An online survey was conducted among the students of a public higher education institution (HEI) in Portugal, from March to May of 2020. The data were analyzed with the structural equation modeling technique, considering environmental attitude, knowledge, subjective norm and perceived behavioral control as exogenous latent variables, and pro-environmental intention and behavior as endogenous latent variables. Findings: The results show that the students' environmental attitude and knowledge have no significant impact on their pro-environmental intention, while the students' subjective norm and perceived behavioral control have a positive impact on their pro-environmental intention. The results also reveal that the students' perceived behavioral control and pro-environmental intention have a strong and positive impact on their pro-environmental behavior. Research limitations/implications: This study focuses on the students from a single public HEI, in accounting and administration area, and deepens environmental behavior in relation to resources' consumption. Practical implications: This study provides findings that can be useful for HEIs to be more effective in their policies, strategies and practices to improve students' environmental behavior. Originality/value: The paper contributes to the literature by exploring the main determinants of higher education students' pro-environmental behavior in a Portuguese HEI and extending the TPB considering the additional variable environmental knowledge.