Purpose: This study aims to explore the effect of social media engagement on the determinants of behavioural intention. Specifically, the authors empirically research the three behavioural intention determinants, namely, attitude, subjective norms and perceived behavioural control (PBC), and confirm their effect on students' intention to enrol on a university online programme. Design/methodology/approach: A conclusive research analysis is followed, and a moderation analysis is conducted to test the hypotheses of the model. Empirical evidence from 201 students in the UK higher education is used and a structural equation modelling approach is followed. Findings: The findings suggest a significant effect of social media engagement on attitude, subjective norms and PBC. The latter three are confirmed as determinants of the intention to enrol on a university online programme. Mindfulness is found to positively moderate the effect of the three determinants on behavioural intention. Originality/value: This study advances knowledge pertaining to the theory of planned behaviour (TPB) by highlighting the effect of social media engagement on the determinants of the intention to enrol on a university online programme. Additionally, the moderating role of mindfulness is also tested with regards to its effect on the relationship between behavioural intentions and its determinants.