Over the past two decades there has been a growing acceptance of 'integrative oncology', also known as complementary and alternative medicine (CAM), in cancer care and research at academic medical centres and medical schools. Proponents of integrative oncology argue that it is based in science and provides the 'best of both worlds' by combining science-based treatments and 'holistic' medicine. However, a close examination of the methodologies indicates that, from a standpoint of basic science, the vast majority of 'integrative' treatments are supported by little, if any, scientific evidence. What are the consequences of this integration? Is there any harm? Are there any potential benefits?