In recent years, mindfulness training techniques have been incorporated into a variety of Western psychological therapies. These mindfulness-based therapies have been demonstrated to be effective in reducing psychological distress in a wide range of populations; however, these interventions provide only superficial rationale for these techniques and do not include teachings about their origins or philosophical importance. The Positive Mindfulness Program (PMP) was developed by combining the well-established foundation of Western mindfulness-based programs with the rich Buddhist teachings from which mindfulness originates to include a more holistic and integrated mindfulness program. The present study explored the effectiveness of the PMP in improving well-being as well as reducing distress in Thai and Australian samples. Study 1 used a randomized control trial to test for changes in well-being, psychological distress, mindfulness, rumination, difficulties in emotional regulation, and understanding of the three characteristics of existence in a Thai-Buddhist sample. The results demonstrated that relative to a control condition, the PMP had a significant effect on well-being, major psychological distress (depression, anxiety, and stress), mindfulness, rumination, difficulties in emotional regulation), and the understanding of the three characteristics of existence. The effect size for rumination was large and the effect size for well-being, mindfulness, difficulties in emotional regulation, and the understanding of the three characteristics of existence was medium to large. For depression, anxiety, and stress, the effect size was small to medium. Furthermore, the results demonstrated no significant changes in the control condition. A multilevel model for the PMP revealed that positive and negative outcomes improved most rapidly across the first half of intervention (the first four sessions) showed smaller changes in the second half of intervention (the second four sessions), and that gains were maintained across the six week follow-up assessment.In Study 2, the PMP was conducted using an Australian sample. This study aimed to replicate the results of Study 1 in a culture where Buddhist ideas are not familiar. Multilevel modelling demonstrated that the PMP significantly increased well-being, mindfulness, and the understanding of Buddhist concepts about the characteristics of existence and significantly reduced rumination, difficulties with emotional regulation, and distress (depression, anxiety, and stress). The program was most effective during the first half of intervention (the first four sessions), while the second half of the intervention (the second four sessions) was also effective but to a lesser extent.Treatment effects were maintained at six weeks follow-up across all measures. The effect size was large for measures of well-being, mindfulness, the understanding of the three characteristics of existence, rumination, difficulties in emotional regulation, depression, and stress. The effect size for m...