This article describes a qualitative synthesis of published research on cancer patients' experiences of complementary therapies. We conducted a systematic search for qualitative studies on this subject published between 1998 and 2007. Twenty-six refereed journal articles met the inclusion criteria. These 26 articles were repeatedly read by the research team and key concepts emerging from them were identified. Differences and variations were examined in association with treatment, therapy type and by stage of cancer (early stage, mid-treatment, advanced cancer, palliative care and long term 'survivors'). Six overarching concepts were located, which describe the key aspects of patients' experiences of the use of complementary and alternative medicine after a diagnosis of cancer: Connection; Control; Well-being; Transformation; Integration; and Polarization. These are described in a 'line of argument' synthesis, and differences associated with treatment type and stage of disease are noted. The findings are presented in a table showing the six concepts according to treatment type and stage; as a composite story; and in a diagrammatic model showing the individual, practitioner and organizational levels. The synthesis identified various specific ways in which complementary therapies supported cancer patients, as well as occasional negative effects. The most notable barrier was the perceived polarization of complementary therapies and biomedicine; patients reported better experiences in integrated settings.