The integration of complementary and alternative medicine (CAM) into cancer services is increasingly discussed as a potential part of UK health policy but as yet there has been little sociological research examining this process. This paper examines the results of a study on the provision of CAM to cancer patients in two distinct organisational contexts: the hospice and the hospital. It is based on interviews with medical specialists, nursing staff and CAM therapists. This paper focuses on how integration is managed in each organisation, examining professional boundary disputes and inter-professional dynamics. Discussion focuses on the rhetorical and practical strategies that are employed by a variety of differently positioned interviewees to negotiate the complexities of the interface of CAM and biomedicine. The results show significant differentiation in how differently positioned cancer clinicians view and utilise the biomedical hierarchy of evidence. We argue that the integration of CAM should not be conceptualised as a mere challenge to biomedicine, or, as resulting in a linear process of de-professionalization. Rather, it should be seen as producing a complex array of processes, including strategic adaptation on the part of medical specialists and NHS organisations.