Although public speaking anxiety (PSA) is the most commonly experienced type of anxiety, the effect of mindfulness-based interventions on PSA is not firmly established. To shed light on this relationship, the present study proposes a model examining the mediating effect of self-esteem in explaining this link. The data for the present study were collected from 227 executives pursuing a 2-year management education program. Public speaking being an essential part of this program, the participants voluntarily completed the Mindful Attention Awareness Scale, Rosenberg Self-Esteem Scale and Personal Report of Public Speaking Anxiety. Based on a quantitative approach, the study demonstrates that the effect of mindfulness-based interventions on public speaking anxiety could be better understood by taking into account the mediating variable—self-esteem. The study concludes by discussing conceptual contributions, limitations and future research avenues.