Background and Aims: To examine the effects of mindfulness-based interventions on gambling behavior and symptoms, urges, and financial outcomes. Method: Systematic review and meta-analytic procedures were employed to search, select, code, and analyze studies conducted between 1980 and 2014, assessing the effects of mindfulness-based interventions in the treatment of disordered gambling with adults. Results: Thirteen studies met criteria for this review and seven met criteria for meta-analysis. Effects were moderate to large for gambling behaviors/symptoms (g = 0.68, 95% CI = [0.39, 0.98], p < 0.01), gambling urges (g = 0.69, 95% CI = [0.18, 1.20], p < 0.01), and financial outcomes (g = 0.75, 95% CI = [0.24, 1.26], p < 0.01). Heterogeneity was low and nonsignificant. Conclusions: The findings provide support for mindfulness-based interventions in the treatment of disordered gambling. However, these results are necessarily tentative, limited by the number and quality of eligible studies, and differing conceptualizations of mindfulness.