BACKGROUND Despite the increasing popularity of acupuncture, there remains uncertainty as to its effectiveness and how it brings about change. Particular questions are posed over whether acupuncture research has sufficient model validity and reflects acupuncture as practised. Exploring traditional acupuncture (TA) in practice should help to expose processes essential to the theory of TA. The aim of this study was to examine what TA practitioners aim to achieve, their rationale and how they follow this through in their practice. METHODS A longitudinal study of TA for women with early breast cancer (EBC) was performed. Study participants comprised 14 women with EBC and two experienced TA practitioners, all taking part in in-depth interviews, conducted before and after receipt of up to 10 treatment sessions, and analysed using grounded theory methods. Additional data came from practitioner treatment logs and diaries. RESULTS Practitioners sought long-term goals of increasing strength and enabling coping as well as immediate relief of symptoms. They achieved this through a continuous process of treatment, following through the recursive and individualized nature of TA and adjusted, via differential diagnosis, to the rapidly fluctuating circumstances of individual women. Establishing trust and good rapport with the women aided disclosure which was seen as essential in order to clarify goals during chemotherapy. This process was carefully managed by the practitioners and the resultant therapeutic relationship was highly valued by the women. CONCLUSION This study provided insight into the interdependent components of TA helping to demonstrate the multiple causal pathways to change through the continuous process of new information, insights and treatment changes. A good therapeutic relationship was not simply something valued by patients but explicitly used by practitioners to aid disclosure which in turn affected details of the treatment. The therapeutic relationship was therefore a vital and integral part of the treatment process.