The current popularity of complementary therapies presents an interesting challenge to nurses and midwives. If they are to deliver such therapies themselves, or support patients in choosing appropriate therapies they will need to consider the professional and legal issues, in particular those regarding safety. Evidence for the effectiveness for complementary therapies is also a requirement in order that their integration into nursing practice can be justified. Purchasers are currently hampered by the lack of credible evidence for effectiveness and until that evidence is provided, access to such therapies through the National Health Service (NHS) will remain limited. The form that evidence should take has led to a lively debate about possible methodological approaches. There appears to be a clash between the medical profession and those working in the field of complementary therapy research, with the medical establishment advocating randomized control trials (RCTs). This contrasts with the view held by some advocates of complementary therapies that the RCT approach is reductionist and not applicable to such approaches. The pivot of the debate on the methodological approaches for evaluating complementary therapies is the contrast of two apparently different and diverse world-views, and the assertion that methods developed in one world-view are not transferable to the other. There is also some confusion within the field of complementary therapy over the applicability of RCTs to therapies such as acupuncture, and the mistaken assumption that trials which include a control group, are also required to be double-blind. This paper is based on the need for good quality evidence of effectiveness in complementary therapy. It will set out the concerns associated with the use of RCTs within complementary therapy, together with the benefits and limitations of this approach. The paper will go on to review research options and propose some suggestions for future methodological approaches.