Objective: This randomized controlled trial examined the comparative effectiveness of 2 interventions for improving diurnal cortisol slope and life satisfaction and reducing stress symptoms among older female dementia family caregivers.; Method: Thirty-one family dementia caregivers were randomized to 8 weeks of Inner Resources for Stress mindfulness meditation and mantra training (IR) or psychoeducation and telephone support (PTS).; Results: Intention-to-treat analyses revealed statistically significant pre-post improvements in diurnal cortisol slope and overall life satisfaction, but not depression or self-efficacy, in the IR relative to the PTS group. Adherence to between-session meditation practice was significantly associated with decreases in depression and self-reported improvements in ability to cope with stress. In addition, IR participants rated the overall benefits of the program more highly than the PTS group.; Conclusion: These results indicate that mindfulness meditation and mantra has promise as a feasible and effective caregiver intervention for quality of life and physiological responding to stress.; © 2017 Wiley Periodicals, Inc.