ObjectiveTo systematically review the influencing factors of breast cancer patients in treatment decision-making. MethodsWeb of Science, PubMed, EMbase, The Cochrane Library, JBI Evidence Synthesis, CINAHL, CNKI, WanFang Data, VIP and CBM databases were electronically searched to collect qualitative studies about the influencing factors of breast cancer patients in treatment decision-making from inception to October 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies. Then, the results were combined using integrating methods. ResultsA total of 13 studies were included. Sixty-seven results were extracted, with 22 results retained after incorporation and removal of duplications. The 22 results were grouped according to their similarities to form 6 categories. These categories resulted in two synthesized findings: influencing factors of patient participation in treatment decision-making and integration results and influencing factors of patients' treatment options. ConclusionBreast cancer patient participation in treatment decisions is influenced not only by internal factors, but also by family and external situational factors. When patients choose treatment, they consider not only their personal values and preferences, but also the impact of treatment on their families and their expectations. The choice is also influenced by social and cultural aspects.