Absenteeism from university teaching sessions is increasingly becoming a common phenomenon and remains a major concern to universities. Poor attendance has significant and detrimental effects on students themselves, their peers and teaching staff. There is, however, a lack of previous research investigating demographic and psychological predictors of non-attendance alongside salient reasons students offer for their absence; it is this 'gap' that the present study attempts to fill. We approached 618 undergraduate university students from a single UK university studying various courses to complete a bespoke questionnaire assessing their estimated percentage attendance at lectures and seminars over the academic year. Students answered demographic questions, completed psychometric tests of perceived confidence (Perceived Confidence for Learning) and university belongingness (Psychological Sense of School Membership), and rated the degree to which possible reasons for non-attendance applied to themselves. Multiple regression analyses were carried out separately for estimated attendance at lectures and seminars. Results demonstrated that significant predictors of poorer attendance for both scenarios were experiencing a lower sense of belongingness to university; working more hours in paid employment; having more social life commitments; facing coursework deadlines; and experiencing mental health issues. Improving a sense of belonging to university and targeting interventions at students working in paid employment may be effective means of increasing attendance. Providing support for students with mental health issues, structuring courses around coursework deadlines and helping students to organise their attendance around social activities could also be advantageous.