Purpose: This study aims to combine two theories, the Theory of Planned Behaviour (TPB) and the Norm Activation Model (NAM), to investigate the relationship between the awareness of reducing single-use plastic waste's environmental cost and the behaviour to limit the use of single-use plastic products (SUPPs) by FPT university students. Design/methodology/approach: Quantitative research methodologies were employed on a sample of 506 university students. The survey data was then examined using SPSS, SPSS AMOS and SmartPLS software. Findings: The overarching conclusion of the study is that awareness of reducing single-use plastic waste's environmental cost has a positive impact on FPT university students' behaviour to reduce their use of single-use plastic products. Another intriguing discovery is how socialisation of responsibility affects pro-environmental behaviour through the interplay between personal norms, subjective norms and behavioural intention. Originality/value: This study on the relationship between SUPP low-consumption awareness and behaviour and mediating factors is a necessary foundation for future studies related to changing the behaviour of students using SUPPs. That will also be a solid foundation for practical plans to change behaviour using SUPPs through communication campaigns to increase awareness. [The page range (199-216) shown on the website is incorrect. The correct page range is 220-237.]