© 2019 Elsevier Inc. Introduction: Stress negatively impacts upon physical and mental health. Pharmacy students demonstrate higher stress than the general population. Mindfulness may improve pharmacy students' stress and distress levels. The purpose of this study was to assess the quantitative effects of a mindfulness-based intervention on pharmacy student stress, distress, burnout, and mindfulness levels. Methods: A quasi-randomised controlled trial was conducted at an Irish pharmacy school during the 2016 to 2017 academic year. The intervention group completed a four-week mindfulness course. The waitlist control group received only usual education. Participants completed a demographics form, the Perceived Stress Scale, the General Health Questionnaire, the Maslach Burnout Inventory Student Survey, and the Five Facet Mindfulness Questionnaire at baseline and immediately post-intervention. Results: Full data were gathered and analysed for 99 students (51 intervention, 48 control, 66.7% female). There were no significant differences between the intervention and control groups at baseline. Post-intervention, a large effect on mental distress was found (Partial Eta Squared 0.137) with the intervention group reporting statistically significantly lower distress than the control group (F (1,98) = 15.3, p < 0.005). Stress and distress were significantly improved for females (p = 0.026, p < 0.005), while males improved in the observing facet of mindfulness (p = 0.038). There was a positive association between attendance and these findings (r2 = 0.191, p < 0.005). Conclusion: Female pharmacy students experienced improvements in mental distress and stress after participation in the intervention. Mindfulness may have a future role to play in pharmacy and healthcare education.