Aims and objectives. This study aims to understand the effects of culturally enriched body-mind-spirit group therapy on anxiety, depression and holistic well-being among women with breast cancer and to examine patients' views on what aspects of group therapy worked to enhance their health. Design. The study was designed using multiple methods, which consisted of a randomised controlled trial and a focus group interview. Methods. A total of 16 subjects in the control group received the standard care of a physician's treatment at the outpatient department. In addition to standard care, 12 subjects in the experimental group received 10 sessions of weekly body-mind-spirit group therapy for 180 minutes each. This therapy integrates concepts and practices of traditional Chinese medicine and Western medicine (e.g. positive psychology and forgiveness therapy). The subjects in the experimental group were invited to participate in a focus group interview regarding their perceptions of the change mechanisms that occurred in group therapy. Results. The results of analysis of covariance indicated that after a two-month trial, there was a similarity between the experimental and control groups in reducing the scores of Beck depression inventory and increasing the scores of body-mind-spirit well-being. However, subjects in the experimental group had a better reduction of the scores of state anxiety inventory than subjects in the control group. The qualitative analysis yielded eight domains: (i) imparting of information, (ii) interpersonal learning, (iii) catharsis, (iv) universality, (v) group cohesiveness, (vi) altruism, (vii) instillation of hope and (viii) existential factors. These domains illustrate how the therapeutic effects of group therapy worked to reduce patients' anxiety. Conclusion. The culturally sensitive body-mind-spirit group therapy reduced anxiety among outpatients with breast cancer. Relevance to clinical practice. The involvement of mental health nurses in providing group therapy for cancer patients could enhance the quality of care in psycho-ontological nursing.