Context • Increasing numbers of people worldwide live with a long-term health condition (LTC). Finding new ways to support people diagnosed with LTCs is important, both to improve their health-related quality of life and to manage the demands on health services that their conditions present. This effort includes a recognition of the importance of interventions to promote self-care. A growing number of systematic reviews of mindfulness meditation-based interventions (MMIs) for people with LTCs have been published but are diverse in scope and quality. Objectives • This systematic review of reviews aims to provide a critical overview of reviews evaluating studies using MMIs and to identify outcomes and conditions for which the clearest evidence exists for MMI effectiveness. Design • The Allied and Complementary Medicine Database (AMED), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Excerpta Medica dataBASE (EMBASE), Medline, PsycInfo, and Web of Science databases were searched in November 2013 for systematic reviews of MMIs for LTCs published since January 2005. Review selection and methodological quality assessment were subject to independent checking. Results • Of 3178 identified articles, 27 papers reporting on 26 reviews met the inclusion criteria. A substantially consistent picture emerged. Improvements in depressive disorders, particularly recurrent major depression, were strongly supported. Evidence for other psychological conditions was limited by lack of data. In populations with physical conditions, the evidence for significant improvements in psychological well-being was clear, regardless of population or specific mindfulness intervention. Changes in physical health measures were inconclusive; however, pain acceptance and coping were improved. Further research is needed to determine long-term and mindfulness-specific effects and to clarify the relationship between levels of mindfulness practice and outcomes. Conclusions • MMIs are potentially beneficial to people with depression and a range of long-term physical conditions, particularly in improving psychological well-being.