Context circle Preliminary studies have suggested that Mindful Self-Compassion (MSC) programs can reduce psychological problems, such as anxiety and depression, but they have rarely been investigated in people with cancer. Objective circle The study intended to investigate the effects of a standard MSC program on psychological well-being and levels of compassion in people with breast cancer. Design circle The study was an internal service evaluation that used a pre-post, quasi-experimental design. Setting circle The study took place at Breast Cancer Haven, a national cancer-support charity, in London, UK. Participants circle Of the 63 people who attended the courses, 38 completed the questionnaires both at baseline and postintervention (60%). Of the 49 participants who provided demographic details, 43 were living with breast cancer; one had bowel cancer; and five didn't have cancer. Of those 49 participants, 44 were females and 5 were males; 43% were aged 29-50 years and 57% were aged 51-69 years; and 73% were of European American/White ethnicity. Intervention circle Participants took part in a standard MSC program exploring mindfulness and self-compassion for eight weeks, three hours each week, plus a four-hour retreat. Outcome Measures circle At baseline and postintervention, participants completed four questionnaires measuring: (1) self-compassion-the Self-Compassion Scale - Short Form (SCS-SF), (2) satisfaction with life-the Satisfaction with Life Scale (SWLS), (3) stress and depression Depression, Anxiety, and Stress Scale (DASS), and (4) mindfulness-Cognitive and Affective Mindfulness Scale-Revised (CAMS-R). They also completed a short feedback form about their course experiences. Results circle The study found statistically significant increases in self-compassion (n = 37), with P <.001; satisfaction with life (n = 36), with P <.001; and mindfulness (n = 35), with P <.001, between baseline and postintervention as well as significant decreases in stress (n = 38), with P <.001, and depression (n = 36), with P <.001 (Wilcoxon signed rank test). Participants stated that while they had found the course to be challenging, they also had found new ways to be aware of and respond to their needs for kindness and self-compassion. They felt the course had changed their lives for the future. Conclusions circle The findings support the beneficial effects of a standard MSC course on the psychological well-being of people with breast cancer. Further larger, more rigorous mixed-method studies are required to corroborate these preliminary findings.