The primary objective of the current research was to determine the effectiveness of positive-focused mindfulness therapy on mental well-being, quality of life, and stress coping strategies in women diagnosed with bipolar disorder in Kashan city. This study was conducted as a quasi-experimental research with pre-test, post-test alongside a control group, and the research population included all women diagnosed with bipolar disorder attending psychiatric centers in Kashan. Initially, registration was carried out by contacting individuals who had records in these centers or were referred by specialists, and 30 of them, who met the study criteria, were selected. The sample was randomly divided into experimental and control groups, and the study was conducted on them. The positive-focused mindfulness therapy consisted of 12 sessions of 90 minutes of mindfulness training derived from the protocol by Tabatabai Nejad et al. (2018). Meanwhile, the control group did not receive any form of training. This research was concluded in March 2023. The instruments used in this study included the 26-item Quality of Life questionnaire (1996), the 45-item Mental Well-being questionnaire by Keyes and Magyar-Moe (2003), and the 18-item Life Stress questionnaire (1993). Variance analysis was employed to test the hypotheses in this study. The results showed that there is a significant difference between the pre-test and post-test scores of the experimental group in comparison to the control group in terms of quality of life, mental well-being, and stress coping strategies (P<0.01). The findings from this research indicate the impact of positive-focused mindfulness therapy in improving the quality of life, mental well-being, and stress in women with bipolar disorder. Therefore, positive-focused mindfulness therapy, alongside other therapeutic methods, can be effective in improving the psychological symptoms of women with bipolar disorder.