Stress has been shown to increase the risk of development and relapse of mental illness, having a detrimental effect on human physiology, psychology and emotional well-being. Mindfulness-based techniques have been shown to be effective in reducing levels of stress, as well as anxiety and depression in both clinical and non-clinical populations. The reported benefits of mindfulness-based interventions are numerous, and in the past few decades, several therapeutic interventions have been developed to incorporate mindfulness as a key component in the treatment of a range of medical and psychological disorders. In our study, we proposed that the integration of three evidence-based mindfulness interventions would result in an effective program to reduce stress, depression and anxiety in a mixed clinical population, in a community health setting. A group-based mindfulness program, attended by seven participants, was piloted and the data collected at baseline (pre-program), post-program and 12-month follow-up were compared. Post-program results showed that participants’ levels of depression, anxiety and stress were significantly reduced, perceived ability to cope increased, and that gains made were largely sustained at 12-month follow-up. These results add to the current research showing the effectiveness of mindfulness for reducing stress, anxiety and depression in both clinical and non-clinical populations. Our study provides preliminary support for the amalgamation of Mindfulness-Based Stress Reduction, Mindfulness-Based Cognitive Therapy and Dialectical Behaviour Therapy in order to effectively meet the needs of a mixed diagnostic group.