Stress and mental ill-health carry considerable costs for both individuals and organizations. Although interventions targeting compassion and self-compassion have been shown to reduce stress and benefit mental health, related research in organizational settings is limited. We investigated the effects of a 6-week psychological intervention utilizing compassion training on stress, mental health, and self-compassion. Forty-nine employees of two organizations were randomly assigned to either the intervention or a physical exercise control condition. Multilevel growth models showed that stress and mental ill-health decreased (...) over 3 months in both groups, while self-compassion only increased in the intervention group. There were no significant effects on life satisfaction in any of the groups. The findings show promising results regarding the ability of compassion training within organizations to decrease stress and mental ill-health and increase self-compassion. (shrink)