Problem: Undergraduate and graduate students frequently experience psychological distress that often results in impairment and psychopathology, and effective interventions are thus needed. This work represents a replication of Mindfulness-Based Stress Reduction (MBSR) to reduce psychological distress; secondary objectives include: evaluating participant characteristics related to differential outcomes; exploring predictors of attrition; testing dose-response relations between attendance and practice, and psychological distress. Method: Twenty-one postsecondary students enrolled in MBSR. Using a non-experimental longitudinal design, student data collection included: psychological distress, trait mindfulness, attendance, and home-practice. Results: Repeated measures ANOVA yielded statistically significant reductions to psychological distress and increases in trait mindfulness. Mindfulness did not significantly moderate intervention effectiveness; no measured variable predicted attrition; and there was no observed dose-response relation. Conclusions: MBSR can reduce psychological distress in postsecondary students, however more research using larger samples is needed to fully understand this contemplative intervention.