Background: Self-determination theory posits that informational versus controlling interpretations of intra-personal events have positive and negative implications, respectively, for well-being. Self-talk represents an intra-personal event that could be interpreted as informational or controlling and may attenuate or exacerbate the negative effects of a stressful experience. Aims: The present study investigated relationships between students' informational and controlling interpretations of self-talk, and their post-lecture affective state. An interactive hypothesis, whereby self-talk would be more strongly associated with well-being when students reported experiencing the lecture as stressful, was also tested. Sample: Participants were 146 male and female undergraduate students (M age = 19.25, SD = 2.57) enrolled on research methods/statistics modules. Methods: Immediately post-lecture, participants completed a measure of informational and controlling self-talk, short forms of the State-Trait Anxiety Inventory and the Positive and Negative Affect Scale, and self-report measures of their experience and understanding of the lecture. Results: Findings from moderated hierarchical regression analyses indicated that informational self-talk was positively associated with positive affect regardless of students' experience or understanding of a lecture. Significant interactions were found between controlling self-talk and experience and understanding, in that a negative experience or poor understanding predicted higher state anxiety and negative affect when students used high, but not low, levels of controlling self-talk. Conclusions: The functional significance of students' self-talk may have implications for affect in higher education, suggesting that providers should promote the use of self-talk that emphasizes students' autonomy and competence.