Objective: The objective of this study was to evaluate whether students exposed to a brief stress reduction intervention would have lesser stress, anxiety and depression levels compared to their non-exposed classmates during stressful events. Methods: The Ex Post Facto design was applied in this study. Students who were exposed and not exposed to a brief stress reduction intervention were surveyed during a continuous examination and during the final examination. The Depression Anxiety Stress Scales (DASS) was used to examine effects on anxiety, stress, and depression levels. Results: The exposed students statistically had lower anxiety and depression scores than the non-exposed students during the stressful period. Reduction of stress, anxiety and depression scores was sustained during the stressful period. Conclusion: The significant reduction of anxiety and depression scores suggested that brief intervention was effective in the enhancement of the psychological wellbeing of exposed medical students during stressful period.